196 BUDLETEN 181, TINIT'EiD STATEI9 NIATTONlAiL MTJSIETJM 



Baker) is situated on the back of the neck behind the tentacles and 

 is traversed by a seminal groove and furnished with a very short 

 appendage. An egg was found in the uterus of A. (A.) stramineum 

 from near San Estaban, Carabobo, Venezuela. The shape of this 

 was a slightly flattened sphere of about 2 mm. in diameter and 1.5 

 mm. from pole to pole. It had a heavy transparent leathery shell. 



KEY TO THE MAINLAND SPECIES OF THE SUBGENUS AUSTROCYCLOTUS 



Umbilicus narrow. 



Shell banded granulatum 



Shell not banded limellum 



Umbilicus not narrow. 



Umbilicus very broad panamense 



Umbilicus not very broad. 



Periphery marked by decidedly retractively curved cords__ stramineum 

 Periphery not marked by decidedly retractively curved 

 cords. 



Shell bicolor. 



Greater diameter more than 21 mm aulari 



Greater diameter less than 20 mm glaucostomum 



Shell not bicolor. 



Greater diameter more than 37 mm peilei 



Greater diameter less than 33 mm. 



Spiral sculpture of base strong kugleri 



Spiral sculpture of base not strong. 



Diameter more than 17 mm carabobense 



Diameter less than 14 mm burringtoni 



APEROSTOMA (AUSTROCYCLOTUS) GRANULATUM (Pfeiffer) 



Plate 27, Figures 15-17 



1862. Cyclofus grannlatus Pfeiffer, Proc. Zool. Soc. London, 1862, p. 275. 



1863. Cyclotus granulatus Reeve, Conchologia iconica, vol. 14, sp. 1. 



1897. Neocyclotus (Neocyclotus) granulatus Kobelt and Mollendorff, Nachrb. 



deutschen malak. Ges., vol. 29, p. 137. 

 1923. Poteria (Neocyclotus) granulatus H. B. Bakb:b, Occ. Pap. Mus. Zool. 



Univ. Michigan, No. 137, p. 37. 



Shell of medium size, helicoid, soiled white except the anterior half 

 between summit and periphery and the posterior half of the base, 

 which are dark chestnut-brown. The nucleus consists of 2 small, 

 well-rounded, smooth turns; the post-nuclear whorls are flattened and 

 slightly bent in toward the suture on the anterior third between the 

 summit and the periphery. The rest are well rounded. They are 

 marked by closely spaced axial threads, which cross each other in 

 protracted and retracted series, forming low, more or less rounded 

 nodules at their junction. Periphery well rounded. Base narrowly 

 umbilicated, well-rounded and marked by the continuation of the 

 sculpture mentioned for the spire. Here, however, the nodules are a 

 little larger. Aperture circular; peristome thin on the outer and 



