118 GASTROCOPTA, SIBERIA, AFRICA. 



Recent Species. 

 64. GASTROCOPTA THEELI (Westerlund). PI. 21, fig. 11. 



Shell dextral, ovate-oblong, cylindroid, obtuse, white, 

 opaque, smooth. Whorls 5^, convex, slowly increasing, 

 parted by a very oblique, deep suture, the last whorl large, 

 rounded at base, ascending anteriorly, encircled by a trans- 

 verse callous behind the aperture, constricted between the 

 callous and aperture. Aperture rounded, 5-toothed : parietal 

 tooth lamelliform, high, subrectangular above, impressed in 

 the middle ; two palatal teeth, deep, short, connected by a 

 callous ; two colurnellar teeth, the upper one transverse, the 

 inferior obsolete, tooth-shaped. Peristonie a little reflected, 

 the margins joined by a thin callous, outer margin partly 

 more curved, obsoletely angular above. Length 2*4, diam. 

 114 mm. (Westerlund). 



Siberia: Mikoulina, type loc. (Westerlund). Trans- 

 Caucasia at Poti, in debris of the Rion (Boettger). 



Pupa thecli WESTERL., Kongl. Svenska Vet.-Akad. Hand- 

 lingar, n. f. vol. 14, pt. 2, p. 102, pi., figs. 4a-c, 1877 ; Fauna 

 Palaarct. Binnenconchyl. iii, 1887, p. 129. Leucochilus thcdi 

 (West.) BOETTGER, Jahrb. Nassauischen Vereins Naturkunde, 

 Jahrg. 41, 1888, p. 286. 



The shell is said to be very similar to CarycMum minimum 

 in form, color and size. It has not been well figured. Dr. 

 Boettger states that it is almost identical with the Miocene 

 B. fissidens Sandberger, which he regards as in all probability 

 a direct ancestor of thecli. The inferior columellar tooth de- 

 scribed is evidently the basal fold. It belongs to the section 

 Sinalbinula. 



V. SPECIES OP AFRICA AND THE MASCARENE ISLANDS. 



The few African Gastrocoptas yet known belong, with the 

 exception of B. pleimesi, to the restricted subgenus Gastro- 

 copta. The northern species (Abyssinia) are related to 

 Asiatic forms; those from West Africa, and South Africa 

 like the Mascarene species, seem much more closely allied to 

 tropical American Gastrocopts. They are figured on plate 22. 



