. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 288 ANNALS OF THE SOUTH AFRICAN MUSEUM. Fig. 142. Olcostephanus {Olcostephanus) inordinatus (Tzankov) (?) (after Pictet I860). X 1. merely to represent an early growth stage. Olcostephanus sublaevis is tentatively included in the synonymy of O. baini. Olcostephanus inordinatus (Tzankov) (Fig. 141) was based upon nuclei, some of which are still partially smooth and hence comparison is difficult. At this growth stage the whorl section is coronate, strongly depressed, and the umbilicus is fairly narrow,
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 288 ANNALS OF THE SOUTH AFRICAN MUSEUM. Fig. 142. Olcostephanus {Olcostephanus) inordinatus (Tzankov) (?) (after Pictet I860). X 1. merely to represent an early growth stage. Olcostephanus sublaevis is tentatively included in the synonymy of O. baini. Olcostephanus inordinatus (Tzankov) (Fig. 141) was based upon nuclei, some of which are still partially smooth and hence comparison is difficult. At this growth stage the whorl section is coronate, strongly depressed, and the umbilicus is fairly narrow, with sloping umbilical walls. There seem to be between 15 and 17 umbilical bullae on the outer whorl of the largest individual, which is herein selected as lectotype, from which arise 3-4 prorsiradiate secondary ribs. There are prominent parabolae. Since Tzankov (1943) included the specimen figured by Pictet {in Pictet & Campiche 1860, pi. 17 (fig. 4), pi. 18 (fig. 3)) (Fig. 142) into this species, this suggests that O. inordinatus loses its parabolae in maturity. There is, thus, little to distinguish Tzankov's (1943) species from the O. baini macroconch, of which it may prove to be a synonym. As already pointed out, O. crassicostatus (Spath) (Fig. 80) was originally compared with O. baini but is herein interpreted as a gerontic O. rogersi (Kitchin) microconch. Occurrence As interpreted here, this species appears to be known from Tibet, Pakistan, ?Spain, Madagascar, Argentina, northern Mexico, ?Oregon, and South Africa, while the occurrence of strongly inflated forms with constricted inner whorls in the Swiss Jura and Bulgaria suggests its presence in these areas as Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original South African Museum. Cape Town : The Museum
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
