. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 238 ANNALS OF THE SOUTH AFRICAN MUSEUM ever, close to 0. klaatschi (Wegner) (Fig. 84) from which it differs in the posses- sion of much coarser ribbing. Wegner's (1909) species differs from O. rogersi in being more finely and densely ribbed, lacking parabolae, and with swollen umbilical tubercles at early growth stages. It is almost certainly merely based upon the inner whorls of O. singularis (Baumberger). Astieria dolioliformis Roch (Fig. 13) was erected for extremely inflated, globose forms with a
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 238 ANNALS OF THE SOUTH AFRICAN MUSEUM ever, close to 0. klaatschi (Wegner) (Fig. 84) from which it differs in the posses- sion of much coarser ribbing. Wegner's (1909) species differs from O. rogersi in being more finely and densely ribbed, lacking parabolae, and with swollen umbilical tubercles at early growth stages. It is almost certainly merely based upon the inner whorls of O. singularis (Baumberger). Astieria dolioliformis Roch (Fig. 13) was erected for extremely inflated, globose forms with a very narrow umbilicus ornamented with nineteen primaries, each terminating in a small umbilical tubercle. Each bulla gives rise to two secondary ribs separated by an intercalatory. As suggested by Spath (1939: 25), this species is best assigned to the genus Fig. 85. Olcostephanus {Olcostephanus) globosus Spath ($). The holotype of Olcostephanus pachycyclus Spath from the Spiti Shales of Pakistan (after Spath 1939). x 1. Olcostephanus pachycyclus (Folgner MS) Spath (Fig. 85) is very close to the holotype of O. modderensis, the O. rogersi macroconch, from which it differs only in the possession of far more umbilical bullae (twenty-three at 70 mm diameter). Fatmi (1977) has included this species in the synonymy of O. globosus Spath (Fig. 86). Olcostephanus drumensis (Sayn MS) (Kilian) (Fig. 87) differs from O. rogersi in the possession of more numerous umbilical tubercles and in its denser, finer secondary ribbing. Olcostephanus psilostomus quadricostatus (Tzankov) (Fig. 88) was based upon two individuals, a macroconch and a microconch. The latter is herein selected as lectotype and seems very close to O. mitreanus (<£), although it is unclear from Tzankov's (1943) figure if the Bulgarian form has parabolae. It differs from the O. rogersi microconch in its smaller adult size, wider umbilicus. Please note that these images are extracted from scanned page im
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
