39 



whorls increase more rapidly, the costas are more distant above, 

 and the umbilicus is less broad and open. 



Cyclostoma roseum. Testa parva, solida, elevato-conica, 

 glabra, pallide rosea : spira acuta, anfr. 6 convexiusculis, supra 

 arete tabulatis ; sutura bene impressa : apertura spiram haud 

 equans, ovata ; peristomate eversa, acuta ; fissura umbilicali costa 

 circumambiente finita. Lat. •}, alt. /^ poll. Hab. Feejee Islands. 



This shell, with several others from the Pacific Islands, forms 

 a group characterized by their slender, elevated form, and the rib 

 which circumscribes the umbilical region. It is more deeply 

 and uniformly colored than C. rub ens, Quoy, which is also 

 smaller, thinner, and has a much larger umbilicus. 



Cyclostoma terebrale. Testa parva, turrita, acuminata, 

 flavida vel dilute cornea, lrevigata, umbilico rimato circumvallato 

 perforata : spira elevata, acuta, anfr. 6-8 convexiusculis, antice 

 sub-angulatis, sese partim obtegentibus ; sutura impressa ; aper- 

 tura sub-rotunda, postice angularis, campanulata ; peristomate 

 simplici, anfractui penultimo late adnato. Lat. T l U} alt. £ poll. 

 Hab. Taheiti and Eimeo. 



Distinguished from allied species by its acuminated spire, an- 

 gular, imbricated whorls and expanded aperture. It bears a 

 general resemblance to Pupafallax, Say. 



Cyclostoma vallatum. Testa parva, solida, elongato-conica, 

 lucida, fusco-cornea : spira anfr. 6 convexis, sub-angulatis, ulti- 

 mo costa valida umbilicnm ambiente munito ; sutura profunda : 

 apertura oblique ovata; peristomate continuo, simplici, campan- 

 ulato. Lat. |, alt. \ poll. Hab. Tongataboo. 



Cyclostoma scitultjm. Testa parva, elongato-conica, tenuis, 

 rufo-cornea, striis incrementi tenuibus solum insculpta, arete 

 umbilicata : spira elevata, anfr. 6-7 rotundatis, supernis sub- 

 angulatis ; sutura profunda : apertura rotundato-ovata, parva, 

 trientem longitudinis adequans; peristomate simplici, pallido. 

 Long, -i, lat. yV poll. Hab. Taheiti and Eimeo, Manua. 



Almost exactly like Amnicola Sayana, Anth. It is larger 

 and more ventricose than C. vallatum, and is distinguished from 

 C. terebrale by its less slender form and unexpanded lip. 



Truncatella aurantia. Testa parva, decollata, conico- 

 cylindracea, aurantia, sub-perforata, longitudinaliter confertim 



