NATURAL SCIENCES OF PHILADELPHIA. 223 



cnlav ; peristome sharp, slightly involute, simple ; columella and 



parietal region smooth, callous. 

 Length 10 mill. 



Hah. Yiti Isles. (Coll. Phil. Acad. Nat. Sciences.) 

 We gathered about forty examples of this remarkable species 



on the sandy beaches at Kiva Island. It probably inhabits deep 



water. It may be easily known by its dark columella, simple 



lips, large sinus, and turreted spire. 



CiTHARA ABBREViATA, Garr., pi. 3, fig. 41. 



Shell small, abbreviate, sub-rhomboidal, solid, white ; spire 

 short, pyramidal, outline flattened, apex sub-acute; whorls 7, flat, 

 the last very large, ventricose, depressed beneath the suture, sub- 

 angulated on the shoulder and rapidly tapering to the base ; sur- 

 face cancellated 1)}' small close longitudinal ribs and five transverse 

 raised lines ; aperture narrow, sub-elliptical, a little more than half 

 the length of the shell ; sinus semicircular; peristome trenchant, 

 stoutly ribbed externallj', and the inner margin callous ; columella 

 slightly concave, smooth, thinly callous. 



Length 5 mill. 



Hah. Paumotus Isles. (Coll. Garrett.) 



A very rare species. Its most obvious character is its short 

 subrhomboid contour, short body, and cancellated surface. 



Odostomia densecostata, Garr., pi. 3, fig. 42. 



Shell small, oblong, thin, sub-pellucid, somewhat glossy, cine- 

 reous ; spire long, gradually tapering from the body whorl, slightly 

 convex in outline, apex sub-acute ; whorls 7, convex, longitudinally 

 ribbed, ribs small, smooth, closely set, rounded, slightly constricted 

 next the suture ; interstices with closely-set transverse impressed 

 striaa ; suture deeply impressed ; aperture vertical, ovate, angular 

 above, about one-fourth the length of the shell; peristome thin ; 

 columella callous, arched, and the fold stout. 



Length 4 mill. 



Hah. Samoa and Yiti Isles. (Coll. Phil. Acad. Nat. Sciences.) 



Not uncommon under stones on reefs. 



Odostomia exilis, Garr., pi. 3, fig. 43. 



Shell small, elongate subulate, fragile, pellucid, shining, white ; 

 spire long, gradually tapering from tlie body whorl, apex sul)- 

 acute ; whorls 6-8, convex, longitudinally finely striated ; suture 



