3^rd figure from the left in Kützing (1844, pl. 6, Fig. 15) designated by Tuji (2007).

“Falaise (France): De Brébisson! Herb. Binder., Schleswig: Herb. Binder.!”

An individual on preparation BM18530, from Kützing packet 333, in the Natural History Museum (BM), designated by Tuji (2007, Fig. 9).

Falaise, France, coll. De Brébisson.

Valvae lanceolate, dorsiventral, dorsal and ventral margins convex; ends barely protracted, rounded, to slightly subrostrate or subcapitate; length 22.5–26.5 µm, breadth 7.0–8.5 µm, L/B ratio 2.9–3.4; axial area narrow, linear-arched, indistinct central area; striae 9–12 in 10 µm, becoming 11–18 towards ends, one isolated pore at end of central striae on ventral side; 19–27 punctae in 10 µm.

Although Krammer (2002, p. 41) used material sampled by the same collector and from the same locality and related his new preparation to the type locality, his effort did not constitute a typification of C. affinis as ruled by the ICN (Art. 7.10, McNeill et al. 2012). On the other hand, Tuji (2007) was the first to consider the original material of this taxon and performed a lectotypification and epitypification, and as such, must be followed according to Articles 9.19 and 9.20 (McNeill et al. 2012).

The lectotype valve of C. affinis is similar to the lectotype valve of C. excisa, except for the excision in the middle part of the valve present in the majority of specimens (Figs 8–21). Populations of this complex from different parts of the world may or may not have excisions, but this character is present in the majority of specimens from the populations examined (Krammer 2002). Therefore, we consider C. excisa and C. affinis as belonging to the same species with differences at the varietal rank based on phenotypic expression and ecological modifications. Genetic studies are still to be completed.

Figures 1–28. 

Cymbella affinis species complex 1–7C. affinis Kütz. var. affinis8–14C. affinis var. excisa (Kütz.) Grunow, specimens from Trieste in preparation BM 18543 11 Lectotype, designated here 15–21C. affinis var. excisa [– C. excisa sensu Krammer], specimens from Trieste in preparation 1131 IOK 16 Isolectotype, designated here 22–28C. affinis var. neoprocera W.Silva, specimens from Germany in preparation 212A IOK, holotype 22 Lectotype, designated here. Scale bar: 10 µm.

The two taxa were both proposed by Kützing (1844, p. 80) and therefore have the same priority. In similar cases, Article 11.5 of the ICN rules that “the first such choice to be effectively published establishes the priority of the chosen name”.

Grunow (1882) proposed the new combination and the new status of C. excisa for C. affinis var. excisa (Kütz.) Grunow. This was the first publication that defined the priority of the epithet affinis over excisa at the specific level. Therefore, the name C. affinis must be considered to be the name of the species when C. excisa and C. affinis are considered to be the same species, in conformity with Article 11.5 of the ICN (McNeill et al. 2012).

Cymbella affinis valves sensu Patrick and Reimer (1975, p. 57) have similar outlines as C. affinis in the type population, but higher range of length and breadth values (length: 20–50 vs. 22.5–26.5 µm; breadth: 7–12 vs. 7.0–8.3 µm, respectively). However, these authors (Patrick and Reimer 1975), included representatives of different localities that could encompass different varieties subscribed to this taxon. The density of striae in the material from USA was similar in the middle part of the valve compared to the type material (9–11 vs. 9–12 striae in 10 µm, respectively) and lower when comparing them close to the ends of the valvae (12–14 vs. 11–18 striae in 10 µm, respectively) (Patrick and Reimer 1975).

C. excisa var. procera Krammer (Figs 22–28), C. excisa var. angusta Krammer (Figs 39–35) and C. excisa var. subcapitata Krammer (Figs 36–42) also appear to be conspecific with C. affinis, but the types show slight differences in their outlines and metric characteristics (Table 1). Thus, all these taxa are here transferred to C. affinis using their respective infraspecific epithet.

Cymbella excisa Kütz., Bacill., 80, Pl. 6, Fig. 17, 1844.

(designated here). An individual marked with blue ring on preparation BM 18543, from Hauck No. 72, 26.4.1837, in the Natural History Museum (BM), London, United Kingdom, represented by Fig. 11.

(designated here). An individual on preparation 1131G IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany, represented by Fig. 16.

“Unter Oscillatorien in Bächen bei Triest”, Italy, 26.4.1837.

Valvae dorsiventral, dorsal margin broadly convex, ventral margin straight, usually with an excision in middle portion; ends subrostrate to rostrate; length 21.5–28.5 µm, breadth 7.0–9.5 µm, L/B ratio 2.6–3.9; axial area narrow, linear-arched, central area indistinct; striae 9–13 in 10 µm, becoming 11–17 toward ends, one isolated pore at end of central striae on ventral side; 21–26 punctae in 10 µm.

Similarly to C. affinis, the lectotypification of Cymbella excisa designated by Krammer (2002, p. 26) cannot be considered according to Article 7.10 of the ICN (McNeill et al. 2012), because the phrase “designated here” or equivalent is required from 1 January 2001 and it was not included by Krammer (2002). Therefore, the lectotype designated by us cannot be considered a replacement of Krammer’s (2002) “lectotype”; rather, it is the first lectotypification of this taxon.

The main difference between C. affinis var. excisa and the nominate variety is the presence of an excision in the middle portion of the ventral side of the valve, a characteristic common to populations of this taxon around the world (Krammer 2002). Therefore, we consider that the presence of excisions in all populations, not present in the type material of C. affinis, constitutes sufficient grounds to consider C. affinis var. excisa different from the nominate variety, which conforms to the statement by Grunow (Schmidt 1875); and not a different species.

Krammer (2002) recorded populations in the isotype material of C. affinis var. excisa with length 17–41 µm, and breadth 6.0–10.7 µm, which were higher than populations in the lectotype material. Krammer (2002) was able to observe initial and post initial cells which were similar to the minimum and maximum length and breadth of this taxon. However, Krammer (2002) included specimens of the variety excisa and the nominate variety in his description.

Cymbella excisa var. procera Krammer, Diatoms Europe 3: 159, Figs 9:1–7, 2002 (Figs 22–28).

Preparation 212A IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany.

(designated here). An individual on preparation 212A IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany; represented by Fig. 22.

Germany, Eifel, Totenmaar, 22.2.1974.

Valvae dorsiventral, dorsal margin broadly convex, ventral margin straight; ends not protracted, rounded, or subrostrate to rostrate; length 21.5–41.0 µm, breadth 8.0–11.0 µm, L/B ratio 2.7–4.0; axial area narrow, linear-arched, indistinct central area; striae 9–13 in 10 µm, becoming 11–14 toward ends, one isolated pore at end of central striae on ventral side; 22–27 punctae in 10 µm.

The combination of C. excisa var. procera with Cymbella affinis would be illegitimate unless it was given a new name, because it would be a later homonym of C. affinis var. procera Krammer. Specimens designated by Krammer (2002), i.e., the preparation 212A IOK (BRM), were found to belong to more than one taxon therefore to clarify the taxonomy we designated a lectotype as established in Art. 9.11 of the ICN (McNeill et al. 2012).

A broader range of metric characteristics were highlighted in this study compared to the characterization of the type population (Krammer 2002, p. 28). We find smaller (21.5–41.0 vs. 24–41 µm) and narrower (8.0–11.0 vs. 8.4–11.0 µm) representatives of this taxon compared to the Krammer’s (2002) records. Still considering Krammer’s (2002) findings, we observe more densely striated (9–13 vs. 9–11 striae in 10 µm) and less punctate (22–27 vs. 24–27 punctae in 10 µm) valves.

Cymbella excisa var. angusta Krammer, Diatoms Europe 3: 159, Figs 9: 8–13, 2002.

Preparation 752 IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany.

(designated here). An individual on preparation 752 IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany, represented by Fig. 29.

Figures 29–42. 

Cymbella affinis species complex 29–35C. affinis var. angusta (Krammer) W.Silva, specimens from Croatia in preparation 752 IOK, holotype 29 Lectotype, designated here 36–42C. affinis var. subcapitata (Krammer) W.Silva, specimens from Hungary in preparation 717 IOK, holotype 39 Lectotype, designated here. Scale bar: 10 µm.

Croatia, watercourse near Lake Gavanovac, Plitvice.

Valves dorsiventral, dorsal margin broadly convex, ventral margin straight, usually with excision in middle portion; ends not protracted to slightly protracted, rounded, subrostrate or subcapitate; length 20.5–35.0 µm, breadth 6.0–8.5 µm, L/B ratio 3.2–4.6; axial area linear-arched, indistinct central area; striae 9–15 in 10 µm, becoming 11–18 towards ends, one isolated pore at end of central striae of ventral side; 19–29 punctae in 10 µm.

The material recorded here presented slight differences in the valve metrics compared to Krammer’s (2002, p. 28) characterization from the same preparation; differences included valve length (20.5–35.0 vs. 17.0–34.0 µm), breadth (6.0–8.4 vs. 6.7–8.2 µm), striae (9–15 vs. 11–14 in 10 µm) and number of punctae (19–29 vs. 25–28 in 10 µm).

Similar to C. affinis var. neoprocera, specimens designated by Krammer (2002), i.e., the preparation 752 IOK (BRM), were found to belong to more than one taxon. Therefore we designated a lectotype for this taxon as established in Art. 9.11 of the ICN (McNeill et al. 2012).

Cymbella excisa var. subcapitata Krammer, 2002, Diatoms of Europe 3: 159, Figs 10: 14–18.

Preparation 717A IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany.

(designated here). An individual on preparation 717A IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany, represented by Fig. 39.

Hungary, Balaton.

Valves dorsiventral, dorsal margin broadly convex, ventral margin straight, usually with excision in middle portion; ends barely protracted, rounded, to broadly protracted, subcapitate; length 21.0–31.7 µm, breadth 7.4–9.0 µm, L/B ratio 2.7–4.0; axial area linear-arched, indistinct central area; striae 8–12 in 10 µm, becoming 9–15 towards ends, one isolated pore at end of central striae of ventral side; 26–31 punctae in 10 µm.

Krammer (2002) distinguished this variety from the variety excisa based on the shape of the ends of the valvae. However, he (Krammer 2002, p. 28) did not provide metric characterizations of this the variety subcapitata, which we observed to agree with the characterizations of C. excisa sensu Krammer (2002), except for the density of striae that was slightly lower in the variety subcapitata.

Specimens designated by Krammer (2002), i.e., the preparation 717A IOK (BRM), were found to belong to more than one taxon. Therefore we designated a lectotype as established in Art. 9.11 of the ICN (McNeill et al. 2012).

Cymbella affinis Kütz. sensu Krammer, Diatoms Europe 3: 41, Figs 21:2–21, 22:1–20, 23:1–18, 2002. (Figs 50–56).

Figures 43–63. 

Cymbella tumidula species complex 43 Original illustration provided by Grunow in Schmidt (1875, Pl. 9, Fig. 33), lectotype, here designated 44–49C. tumidula var. tumidula, specimens from Trieste in preparation BM 18543 49 Epitype, here designated 50–56C. tumidula var. tumidula [C. affinis sensu Krammer (2002)], specimens from Trieste in preparation 1131G IOK 54 Isolectotype, designated here 57–63C. tumidula var. procera (Krammer) W.Silva, specimens from Serbia in preparation 714 IOK, holotype 57 Lectotype, designated here. Scale bar: 10 µm.

(designated here). Plate 9, Fig. 33 from Schmidt (1875a) (Fig. 43).

Italy, Trieste, 26.4.1837.

(designated here). An individual marked with a red ring on preparation BM 18543 from Hauck No. 72, 26.4.1837, in the Natural History Museum (BM), London, United Kingdom, represented by Fig. 49.

(designated here). An individual on preparation 1131G IOK, from Hauck No. 72, 26.4.1837, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany, represented by Fig. 54.

Italy, Trieste, 26.4.1837.

Valves lanceolate, dorsiventral, dorsal and ventral margins convex; subcapitate ends; length 25.4–34.7 µm, breadth 7.8–8.7 µm, L/B ratio 3.4–4.0; axial area linear-lanceolate, straight to arched, central area irregular to rounded; striae 10–15 in 10 µm, becoming 12–19 toward ends, 2–4 isolated pores at end of central striae on ventral side; 26–33 punctae in 10 µm.

The lectotypification of C. affinis allowed us to consider C. affinis and C. tumidula [– C. affinis sensu Krammer], lectotypified and epitypified here, as independent species. C. tumidula has a more lanceolate outline, subcapitate ends, and a lower degree of dorsiventrality than C. affinis. The striae in the middle part of the valve are shorter and unevenly distributed in C. tumidula, forming a distinct central area (Figs 43–63), in contrast to C. affinis where the central area is indistinct and the striae are uniformly distributed. In addition, all specimens of the type material of C. affinis have only one stigma, whereas in C. tumidula 1–5 stigmata can be observed.

Specimens from the population of the holotype material of C. affinis var. procera were very similar in outline but larger and wider than C. tumidula var. tumidula, resulting in higher maximum length/breadth ratios. However, all metric characteristics of C. affinis var. procera intergraded with C. tumidula var. tumidula, and therefore this taxon was transferred to C. tumidula var. procera.

The characteristics of C. affinis sensu Krammer (2002, p. 41) were similar to the type population of C. tumidula, but with a wider range of values. This includes length (17–34 vs. 25.4–34.7 µm, respectively) and breadth (7.5–9.5 vs. 7.8–8.7 µm). C. affinis sensu Krammer (2002, p. 41) also presented narrower range of values of striae in 10 µm (10–13, becoming 13–15 toward ends vs. 10–15 in 10 µm, becoming 12–19 toward ends, respectively) and density of punctae (27–32 vs. 26–33 punctae in 10 µm) than C. tumidula.

Cymbella affinis var. procera Krammer, Diatoms Europe 3: 161, Figs 22: 8–13, 2002.

Preparation 714 IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany.

(designated here). An individual on preparation 714 IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany, represented by Fig. 57.

Serbia, Rogatica (abundant in chalk-rich spring), 1976.

Valves lanceolate, dorsiventral, dorsal and ventral margins convex; ends subrostrate or subcapitate; length 27.0–40.3 µm, breadth 9.0–10.2 µm, L/B ratio 2.9–4.2; axial area linear-lanceolate, slightly arched, central area rounded; striae 9–13 in 10 µm, becoming 13–18 toward ends, 2–5 isolated pores; 25–31 punctae in 10 µm.

According to Krammer (2002), this variety differs concerning wider valves (higher than 9.5 µm) from the nominate variety of C. affinis sensu Krammer. We recorded specimens of C. tumidula var. procera with 9 µm breadth, which were higher than the nominate variety (9.0–10.2 vs. 7.8–8.7 µm).

Specimen designated by Krammer (2002), i.e., the preparation 714 IOK (BRM), were found to belong to more than one taxon. Therefore we designated a lectotype as established in Art. 9.11 of the ICN (McNeill et al. 2012).

Cymbella salinarum Grunow in Schmidt, A. Schmidt’s Atlas Diatom.-Kunde, Pl. 9, fig. 28, 1875.

Preparation 1603 in the Grunow Collection in the Naturhistorisches Museum Wien (W).

(designated here). An individual on preparation 1603, in the Grunow Collection in the Naturhistorisches Museum Wien (W), represented by the illustration in Krammer (2002, Fig. 25: 13).

Salinen von Zaule (Trieste, Italy).

Valves lanceolate, dorsiventral, dorsal and ventral margins convex; ends subcapitate; length 34.0 µm, breadth 10.7 µm, L/B ratio 3.2; axial area linear-lanceolate, slightly arched, central area rounded; striae 14 in 10 µm, becoming 15 toward ends, 1 isolated pore.

This taxon presents morphometric characteristics similar to C. tumidula var. tumidula, except it has wider valves. Cleve (1894) recorded specimens of C. tumidula var. salinarum with 27–40 µm length, 8–10 µm breadth, and 11 or 12 striae in 10 µm, and considered that the only difference between this taxon and C. tumidula var. tumidula was the shape of the ends. Although in poor condition, in preparation 1603 we did not find differences between the shape of the valvar ends of the variety salinarum and the nominate variety. However, C. tumidula var. salinarum has higher breadth values compared to the type population of C. tumidula var. tumidula, even in populations of this taxon as recorded by Krammer (2002) from Falaise where initial and post initial cells were found. Moreover, the occurrence of C. tumidula var. salinarum has been restricted to brackish waters.

Krammer (2002, Fig. 25: 13) provided the illustration of an individual of the type of C. salinarum. The individual represented by him (Krammer 2000) was similar to C. tumidula var. tumidula. However, it was larger and had only one isolated pore, differing from C. tumidula, which has more than two isolated pores (Figs 50–56). Thus, in contrast to Krammer (2002), who treated C. salinarum at the specific level, we consider this taxon at the infraspecific rank as did Cleve (1894).

Plate 9, Fig. 23 in Schmidt (1875), designated by Tuji (2007).

Puerto Rico and Kahyenmathay.

An individual on slide 1504 in the Grunow Collection in the Naturhistorisches Museum Wien (W), designated by Tuji (2007, Fig. 15).

Puerto Rico.

Valves lanceolate, dorsiventral, dorsal margins broadly convex and ventral margin convex; ends barely protracted, narrowly rounded, or subcapitate; length 36.5–45.0 µm, breadth 10.8–13.3 µm, L/B ratio 3.2–3.4; axial area linear, arched, central area indistinct to rounded; striae 9–12 in 10 µm, becoming 11–17 toward ends, 1–3 isolated pores; 21–24 punctae in 10 µm.

Preparation 1015D IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany.

(designated here). An individual on preparation 1015D IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany, represented by Fig. 64.

Figures 64–70. 

Cymbella tropica Krammer from Venezuela in preparation 1015D IOK, holotype 64 Lectotype, designated here. Scale bar: 10 µm.

Venezuela, Rio Manizanes, coll. Rumrich, 4.4.1990.

Valves lanceolate, dorsiventral, dorsal and ventral margins convex; ends barely protracted, rounded, or subcapitate, slightly deflected to ventral margin; length 34.5–42.7 µm, breadth 10.0–12.0 µm, L/B ratio 3.1–4.0; axial area linear, arched, central area indistinct to slightly rounded; striae 9–12 in 10 µm, becoming 11–12 toward ends, 1 isolated pore; 21–24 punctae in 10 µm.

Krammer (2002) described C. tropica and recorded differences in the size, length/breadth ratio, and the presence of only one stigma as consistent diagnostic differences between this species and C. turgidula. Tuji (2007) recorded the occurrence of specimens of C. turgidula with 1–3 isolated pores, which was also observed by Krammer (2002) in his material. We observed a continuum between the metric characteristics of C. tropica and C. turgidula, even in those characters that were considered by Krammer (2002) as differentiating. However, the outline was more lanceolate, the ends more protracted and slightly deflected to the ventral side, and the degree of dorsiventrality was lower in C. tropica compared to C. turgidula.

= Cymbella turgidula var. nipponica Skvortzov, Philipp. J. Sci. 61: 283, Figs 2:8, 4:4, 1936. (Figs 78–97)

– Cymbella uenoi Skvortsov in Skvortsov & Noda, Sci. Rep. Niigata Univ., ser. D (Biol.) 8: 19, Pl. 3, Fig. 3, 1971. (nom. inval.)

= Cymbella rheophila Ohtsuka in Ohtsuka & Tuji, Phycol. Res. 50: 245, Figs 7, 8, 2002.

= Cymbella uenoi Skvortsov ex Tuji, Diatom 23: 50, Figs 20–25, 2007.

= Cymbella uenoi f. nipponica (Skvortsov) Tuji, Diatom 23: 54, Fig. 26, 2007.

Preparation 1046E IOK [not “1046c IOK”], in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany.

(designated here). An individual on preparation 1046e IOK, in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), Bremerhaven, Germany, represented by Fig. 73.

Figures 71–84. 

Cymbella subturgidula Krammer 71–77 Specimens from Korea in preparation 1046E IOK, holotype 73 Lectotype, designated here 78–80 Specimens from Japan in preparation R 214.928 78Isolectotype, designated here, of C. turgidula var. nipponica Skvortsov [≡ C. rheophila Ohtsuka], heterotypic synonym of Cymbella subturgidula 81 Specimen from Japan in preparation R 214.930 82–84 Specimens from Japan in preparation R 214.932. Scale bar: 10 µm.

Korea, Ulchin County, Kyungsang Pukdo, Kwangchun River.

Valvae slightly lanceolate to lanceolate, dorsiventral, dorsal margin broadly convex and ventral margin straight to convex; ends barely protracted, subrostrate to broadly subcapitate; length 26.3–41.0 µm, breadth 9.0–13.5 µm, L/B ratio 2.3–3.6; axial area linear to linear-lanceolate, arched, central area indistinct to slightly rounded; striae 9–13 in 10 µm, becoming 12–15 toward ends, 1–3 isolated pores; 21–26 punctae in 10 µm. In SEM, the striae showed lineolate punctae externally and internally, the striae are composed by an alveolus internally, surrounded by thick costae; the isolated pores are rounded externally; internally, the alveoli of the isolated pores are irregularly obovate and connected to intercostae, the margins with tooth-like structures (brocca); one apical pore field (APF) not divided by the external terminal fissure of the raphe can be observed on each pole of the valvae; the terminal nodule extends to the dorsal side, under the APF and has a short branch that penetrates the APF apically; the helictoglossae lie under the terminal nodule and are deflected to the dorsal side.

Krammer (2002) described C. subturgidula based on preparation 1046c, which he designated as the holotype. This preparation was sought in the Alfred-Wegener-Institut für Polar- und Meeresforschung (BRM), where the entire Krammer Collection was transferred. However, preparation 1046c IOK is from Argentina in South America, and not from the holotype designated from Korea. In the protologue of C. subturgidula, Krammer (2002, p. 278 and 279) illustrated three specimens from preparation 1046E IOK, from Korea. Thus, the existence of slide 1046c IOK from Argentina, which is incongruent with the type locality, and the existence of slide 1046E which was used by Krammer to illustrate C. subturgidula, led us to consider the indication of preparation 1046c IOK as a typographical error.

Cymbella subturgidula and C. turgidula are closely related species. However, C. turgidula is more lanceolate and has a higher degree of dorsiventrality than C. subturgidula. Moreover, C. turgidula is slightly broader than C. subturgidula, with a more prominent ventral side of the valve. The ends in the two species are different, being subrostrate-rounded in C. turgidula and slightly subrostrate-truncate in C. subturgidula. The central area is more distinct in C. turgidula than C. subturgidula. Although the number of punctae in 10 µm is the same in both species, the striae in C. subturgidula seem to be more coarsely punctuated than in C. turgidula.

Cymbella turgidula var. nipponica was described by Skvortzow (1936). He considered that this taxon differed from the nominate variety due to the elongated valve, slightly undulate ventral margin, and broad rostrate ends. Ohtsuka and Tuji (2002) proposed that maintaining this taxon as a variety of C. turgidula was not appropriate. They based their arguments on the co-occurrence of the nominate variety and the variety nipponica. Therefore, they proposed the name C. rheophila T.Ohtsuka for this taxon at the specific rank.

Skvortsov and Noda (1971) described C. uenoi Skvortsov, but did not indicate any type. According to Article 40.1 of the ICN, names of new genera or taxa of lower ranks published after 1958 are valid only when the type is indicated (McNeill et al. 2012), and therefore C. uenoi is invalid. Tuji (2007), however, indicated a type for C. uenoi, fulfilling the conditions required by the ICN. Therefore, the author of the name becomes C. uenoi Skvortsov ex Tuji. Tuji (2007) also transferred C. turgidula var. nipponica [≡ C. rheophila] to that species, resulting in the name C. uenoi f. nipponica, considering erroneously that the name C. uenoi had priority under the name C. rheophila.

Tuji (2007, p. 54) suggested the conspecificity of C. subturgidula and C. uenoi. The observations of the type material of C. uenoi provided by Tuji (2007) and C. uenoi f. nipponica [≡ C. rheophila], compared with the type material of C. subturgidula (i.e. morphometric characteristics), led us to agree with Tuji (2007). Since C. uenoi was validated only in 2007, the valid names of this species are either C. rheophila or C. subturgidula, both published in 2002, and not C. uenoi as stated by Tuji (2007). C. subturgidula was described in The Diatoms of Europe, volume 3, published by Krammer on 28 January 2002 (Koeltz Scientific Books, pers. comm.), while C. rheophila was not published before 29 July 2002, the date of acceptance of the paper. Therefore, the epithet subturgidula has priority over the epithet rheophila.

The re-analysis of the type material of C. subturgidula allows us to broaden the metric data of this species compared to its original description. We observed a wider range of values for length (30.3–37.4 vs. 36–37 µm), breadth (9.0–12.8 vs. 10.0–11.0 µm), striae (9–11 vs. 10–11 in 10 µm) and punctae (21–24 vs. 24 in 10 µm) compared to Krammer’s (2002) description. Metric characteristics of the original material of C. turgidula var. nipponica [≡ C. reophila; ≡C. uenoi f. nipponica, isolectotype designated here (Fig. 78)] and C. uenoi (Table 1) also agree with the characteristics of the type population of C. subturgidula (Skvortzov and Noda 1971, Ohtsuka and Tuji 2002, Tuji 2007).

Krammer (2002) described two isolated pores in C. subturgidula. Similarly, Ohtsuka and Tuji (2002) and Tuji (2007) observed two isolated pores in the material of C. turgidula var. nipponica [≡ C. rheophila; ≡ C. uenoi f. nipponica] and C. uenoi. However, in the original sample of the lectotype of C. turgidula var. nipponica we found some specimens with only one isolated pore (Fig. 88), and in recent material collected in Lake Biwa we found up to three isolated pores (Fig. 90).

Figures 85–89. 

Cymbella subturgidula Krammer from Japan, in the original material of C. tumidula var. nipponica Skvortsov [≡ C. rheophila Ohtsuka], in sample 0983 85, 87 External valvar view 86, 88, 89 Internal valvar view.

Figures 90–97. 

Cymbella subturgidula Krammer from Japan in sample 1093 90, 91, 93, 97 External valvar view 92, 94, 95, 96 Internal valvar view.