11*0 CYCLOSTOMACEA. 



this West Indian shell among small shells collected by 

 Mr. Bartlett in Florida. 



Remarks. Instead of figuring American specimens, I 

 have preferred giving a fac-simile of the figures referred to 

 by Pfeiffer. Fig. 1 is, however, from one of our speci- 

 mens. 



Pfeiffer mentions a variety unknown to me, " distinctius 

 costata, peristomate subduplicata." 



It seems nearest allied to the preceding species, and 

 admits of no little variation. 



SUBORDER ECTOPHTHALMA. 



Eyes at the side of the head at the external base of the 

 tentacles ; foot subelongate ; operculum horny or testa- 

 ceous, not concentrically striate, and not always distinctly 

 spirated. (Pfr.) 



It contains two families, Cyclostomacea and Helicinacea, 

 which Binney united in the family Helicinadce. 



FAMILY CYCLOSTOMACEA. 



In addition to the characters of the suborder, Pfeiffer 

 enumerates these : " whorls numerous and subequal, or 

 few and rapidly increasing." 



SUBFAMILY CISTULEA. 



Operculum suboval, cartilaginous, with few whorls and 

 excentric nucleus ; shell globose conic or ovate-turrited. 

 (Pfr.) 



GENUS CHONDROPOMA PFEIFFER. 



Operculum oval, subcartilaginous, flat, with few, rapidly 

 increasing whorls, and a nucleus generally very excentric. 

 Shell oblong-turrited, generally truncated at tip, more 

 rarely globosely conic ; aperture oval ; peristome simple, 



