1861.] MR. W. HARPER PEASE ON NEW MOLLUSCA. 243 



ribbed at the periphery and on the margin of the umbilicus, beneath 

 more or less obsoletely ribbed ; whorls six, carinately rounded, and 

 ornamented with radiating lines of short hairs, sutures well impressed; 

 aperture subrhomboidal, a single lamella on the penultimate whorl. 

 Tessellated with dark chestnut and fulvous brown. 



Diam. 5 mill., length of axis 2 mill. 



Hab. Tahiti. 



In size, colour, and general shape this species agrees with H. obolus, 

 Gould. It may prove to be a variety. It is never, however, concave 

 above, and is more or less ribbed beneath. The epidermic lines, sup- 

 porting short hairs, are common to most of the species of this type, 

 so far as I have observed, on our islands and from the south. They 

 are easily rubbed off, and seldom appear, except on living specimens. 



Helix parvidens. 



Shell small, discoidal, slightly convex above, rounded beneath, 

 ornamented with fine, regular, crowded, raised striae ; whorls five, 

 rounded, sutures well impressed ; aperture lunate, and usually fur- 

 nished with six lamellae, two on ultimate whorl, one on pillar, and 

 three on penultimate whorl ; umbilicus deep, about one-fourth of the 

 width of the shell. Tessellated with reddish brown and light fulvous. 



Hab. Tahiti. 



Helix conula. 



Shell light, thin, imperforate, conoidal, convex beneath ; whorls 

 five, convexly rounded, the last carinate at its periphery, sutures 

 well impressed, the upper whorls ornamented with rather distant, 

 revolving, rib striae, which become obsolete on last whorl, base finely 

 radiately striated ; aperture triangularly lunate ; columella thickened, 

 tortuous, and slightly reflected at its base, forming a tooth-like pro- 

 cess. Colour light yellowish. 



Diam. 7 mill., height 5 mill, 



Hab. Tahiti. 



Cyclostoma tahitensis. 



Shell pyramidal, imperforate, vitreous, of a reddish horn-colour ; 

 ribbed longitudinally, ribs irregular, in number over twenty, promi- 

 nent, interstices concave, very finely striated lengthwise ; whorls six, 

 rounded, and separated by a profound suture; aperture angularly 

 oval ; lip white, continuous, separate or connected for a short di- 

 stance with the penultimate whorl. 



Length 7 mill., breadth 3^ mill. 



Animal pale ; tentacles slightly dusky, stout, tapering (not cla- 

 vate), eyes on their outer posterior bases ; muzzle prominent ; foot 

 small, oblong-oval, not grooved longitudinally, consequently locomo- 

 tion is effected in the same manner as in the Helices. 



Hab. On the ground in dry woods, Huaheine. 



Cyclostoma viridescens. 



Shell small, conic, cylindrical, of a light greenish colour ; whorls 



