282 cyclopiiorinjE. 



Genus DERMATOCERA, H. and A. Adams. 



Animal with a conical, epidermal horn on the hind part of 

 the foot. 



Operculum orbicular, membranous, flat, with many narrow 

 whorls and a central nucleus. 



Shell glohosely turbinate, narrowly umbilicated, whorls 

 rounded, simple ; peristome reflexed, with the margins wide 

 apart and united by a thin callus. 



Syn. Cyclostoma sp., Sow. Leptopoma sp., Pfeiff. 



Ex. D. vitrea, Lesson, pi. 85, fig. 7. Operculum, D. 

 vitrea, fig. 7, a, 7, b. Shell, D. vitrea, fig. 7, c. 



M. Eydoux has figured a Cyclostomus with a similar 

 caudal appendage in the "Voyage of the Bonite." Although 

 there does not appear to be any great difference either in the 

 shell or operculum of the animal on which we have esta- 

 blished this genus, still the existence of a conspicuous, 

 fleshy, horn-like appendage on the hind part of the foot ap- 

 pears of a nature so peculiar as to warrant us in giving a 

 name to those animals in which it is present. The species 

 we have examined, and which is in spirits in Mr. Cuming's 

 Collection, is from the Islands of the Philippine Archi- 

 pelago. 



Species of Dermatocera. 

 maculosa, Eyd and Soul. vitrea, Less. 



Genus AULOPOMA, Troschel. 



Operculum horny, arctispiral, planorbiform, composed of 

 two lamina?, the last whorl furnished internally with a cir- 



