278 BULLETIN 181, mSTITED STIATES NATIONlAIi MUSEUM 



of a turn or adiiate to the preceding whorl. The postnuclear whorls 

 are marked by strong, retractively curved axial riblets, which become 

 decidely irregular and coarse on the last whorl. Suture very deeply 

 impressed. Periphery rounded. Base openly broadly umbilicated, 

 inflated, strongly rounded and marked by the continuation of the 

 axial ribs which cross the umbilical wall. Aperture circular, slightly 

 protracted at the posterior angle ; peristome simple, thin, even on the 

 inner lip, solute or attached to the preceding turn. Operculum? 



The specimen figured is one of two, Acad. Nat. Sci. Philadelphia 

 No. 12975, collected near Campos, Brazil, by Anthony. It has 4.5 

 whorls and measures : Height, 8 mm. ; diameter, 13 mm. 



It seems possible that when adequate material has been examined 

 this species may prove to be a Cyclopomo'ps. 



INCERTICYCLUS GAYI (Hupe) 



1854. Cyclostoma gayi Hup^, in Gay, Historia fisica y politica de Chile, Zool., 



vol. 8, p. 117. 

 1858. CyclopJiorus gayi Pfeiffeb, Monographia pneumonopomorum viventium, 



vol. 2, p. 65. 

 1897. Amphicyclotus gayi Kobelt and Mollendorff, Nachrb. deutschen malak. 



Ges., vol. 29, p. 139. 



We have not seen this species and so give a translation of Hupe's 

 description : 



Shell small, subdiscoid, solid, ferrugineous yellow. Whorls 3, con- 

 vex, carinated externally above. Suture profound. Aperture large, 

 romided with the margins entire and sharp. Umbilicus open. Oper- 

 culum corneous. 



To this Hupe adds : A small shell, a little discoid with 3 rounded 

 convex whorls, marked on the upper side by obtuse poorly developed 

 threads. 



The above Latin diagnosis is followed by an explanation in 

 Spanish : 



Shell small, somewhat discoid, thick with 3 rounded, convex whorls. 

 Upper surface marked by poorly developed spiral threads, the median 

 one of which is stronger than the rest. Spire obtuse, whorls sep- 

 arated by a profound suture; aperture large, circular; peristome 

 tliin and sharp, thickening within the aperture. Umbilicus small 

 and rounded. Entire surface ferrugineous brown; aperture whitish 

 within. Operculum thin, corneous. Diameter, % of a line [1.5 

 mm.]; height, l^ line [1 mm.]. 



This species is one of the smallest of the genus yet known. It is 

 characterized by its subdiscoid form and spiral lirations, the median 

 spiral thread being stronger than the rest. Its ferrugineous color also 

 helps to distinguish it from the other members of the genus. 



Habitat : Under rocks a short distance from the sea in the northern 

 part of Chile. 



