Annals of the South African MuseumAnnale van die Suid-Afrikaanse Museum . Fig. 6. Steinmanella holubi (Kitchin), x 1. The lectotype, SAM-PCU3981, in lateral view. LOWER CRETACEOUS TRIGONIOIDA FROM THE ALGOA BASIN 17. Fig. 7. Steinmanella holubi (Kitchin), x 1. Lateral view of an unnumbered topotype in the South African Museum. Description The shell is large (maximum length 128 mm), massive, quadrate, somewhatlonger than high (H/L = 0,59-0,78), with inconspicuous terminal umbones andan abruptly truncate anterior face. The dorsal and anterior margins are straight,the ventral margin broadly round
Annals of the South African MuseumAnnale van die Suid-Afrikaanse Museum . Fig. 6. Steinmanella holubi (Kitchin), x 1. The lectotype, SAM-PCU3981, in lateral view. LOWER CRETACEOUS TRIGONIOIDA FROM THE ALGOA BASIN 17. Fig. 7. Steinmanella holubi (Kitchin), x 1. Lateral view of an unnumbered topotype in the South African Museum. Description The shell is large (maximum length 128 mm), massive, quadrate, somewhatlonger than high (H/L = 0,59-0,78), with inconspicuous terminal umbones andan abruptly truncate anterior face. The dorsal and anterior margins are straight,the ventral margin broadly rounded, and the broad respiratory margin subtrunc-ate. The valves are weakly inflated (W/H = 0,27-0,34) and the inturned beaksorthogyrous to slightly opisthogyrous. The escutcheon is very narrow, lanceolate, and ornamented with irregularrows of bullae that follow the growth lines and are continuous with the growthrugae of the area. There is a narrow lunule, about one-third of the shell ligament pit is well developed, lanceolate, and may extend 40-50 per centof the length of the escutcheon. The positions of the escutcheon and marginalcarinae are marked by rows of prominent nodes, as is the dorsal edge o
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Keywords: ., bookauthorsouthafr, bookcentury1800, bookdecade1890, bookyear1898
