THE CYCLOPHORID LAND MOLLUSKS OF AMEiRTCA 141 



whorls, the last scarcely descending ; aperture hardly oblique, circular ; 

 peristome continous, acute. Operculum calcareous, scarcely convex 

 on the outside, with ten volutions, depressed and expanded at the edge. 

 Height, 8 mm. ; greater diameter, 14 mm. ; lesser diameter, 11.5 mm. 

 Aperture 6 mm., broad and high. 



Shuttleworth states that he had received two specimens of this from 

 Petit from the Island of Martinique. I have not seen it and am unable 

 to place it in any of the groups here listed. 



INCERTICYCLUS CINEREUS (Drouet) 

 PlATE 18, FiGUEE 25 



1859. Cyclophorus cinereus Drouet, Essai sur les mollusques terrestres et fluvia- 

 tiles de la Guyane frangaise, p. 90, pi. 3, figs. 37-38. 



The following is a translation of Drouet's description : 



Shell small, umbilicated, subturbinate, thin, scarcely translucent, 

 finely striate, ashy ; whorls 4, convex, apex obtuse ; aperture angulatedly 

 circular, peristome simple, acute. Operculum immersed, concolor, nor- 

 mal. Height, 4 mm. ; greater diameter, 4.5 mm. ; diameter of aperture 

 2 mm. * * * This Cyclophorid by its general form, size, and 

 coloration resembles our Valvata piscinalis Miill. It has no decided 

 characters except its small size, subturbinate form and ashy color, and 

 especially the fine regular striations with which its shell is adorned. 



The figures emphasizes the axial lirations. 



There is no material in the collection of the United States National 

 Museum that helps us understand this species. The fact that Drouet 

 describes Cyclopho'i^us liratus and C. acutiliratus immediately before 

 his G. cinereus and says here that the operculum is normal, leads one 

 to believe that he was dealing with an amphicyclotid. We know of 

 none in the "West Indies with axial ribs. I therefore include this 

 species in sedis incertae. It was described from the Island of Marti- 

 nique. 



428349—42 10 



