Amphora proteus W. Gregory

figs 2A–C & 8D: Amphora cf. proteus W.Gregory Morphometric data:— L: 40.7–52.5 µm; W: 8.5–9.8 µm; DS: 11–13; VS: 10–12 (n=5). Notes:— These valves do not fit entirely A. proteus since they usually have a single elongated areola on the ventral side, and not two rows of areolae as in A. proteus (Schoeman & Archibald 1986, Levkov 2009), although a very short second row could be present (figs 2B–C), as in some of the valves of A. proteus in Levkov (2009, Pl. 248: 6). Valves are also slightly smaller than those of the original A. proteus (length> 50 µm, width> 9 µm, Schoeman & Archibald 1986, Levkov 2009). However, the only valve we were able to find under SEM (fig. 8D) showed the presence of dimple-like depressions internally near the elongated central nodule, as in A. proteus (Levkov 2009, Pl. 248: 6). Another similar taxon in both dimensions and striation pattern, A. proteoides f. varians Proshkina-Lavrenko, was described from the Black Sea (Proshkina-Lavrenko 1963). Unfortunately, it is only known from her description and drawings (Proshkina-Lavrenko 1963, Pl. IX: 1–4), presenting insufficient details for species separation nowadays.
Published as part of Zidarova, Ralitsa, Ivanov, Plamen, Hristova, Ognyana, Dzhurova, Boryana & Hineva, Elitsa, 2022, The unexpected diversity in Amphora sensu lato (Bacillariophyta) at Sozopol Bay, the western Black Sea, pp. 103-127 in Phytotaxa 544 (2) on page 106, DOI: 10.11646/phytotaxa.544.2.1, http://zenodo.org/record/6503793
{"references":["Schoeman, F. R. & Archibald, R. E. M. (1986) Observations on Amphora species (Bacillariophyceae) in the British Museum (Natural History). V. Some species from the subgenus Amphora. Journal of South African Botany 52: 425 - 437. https: // doi. org / 10.1016 / S 0254 - 6299 (16) 31507 - 1","Levkov, Z. (2009) Amphora sensu lato. Diatoms of Europe 5: 1 - 916.","Proshkina-Lavrenko, A. I. (1963) Diatoms from the Black Sea benthos. Akademii Nauk USSR, Moscow-Leningrad, 243 pp. [in Russian]"]}