226 AMERICAN JOURNAL 



margins ; suture well impressed ; spire elevate, acute ; apeiture 

 roundly ovate, yellowish orange Avithin ; peristome continuous, 

 adhering to the penultimate whorl. AYhitish or pale flesh color. 



Helicina discoidea. Pease. 



Description. — T. deprcssa, tenuiscula, vix nitidula, oblique 

 tenuiter et irregulariter rugoso-striata ; spira breviter conoidea ; 

 anfr. 5, plano-convexis, ultimas depressis, ad peripheriam cos- 

 tato-carinatus ; apcrtura triangulari-lunaris, perist simplici 

 acuto, vix reflexo, ad basim acute angulato, subemarginato, 

 super basim callo continuato ; columella callum copiosum, sub- 

 granulosum, circumscriptum ; callo sulco arcuato marginato. 

 8ubrufa, interdum straminea vel cornea. 



Dimensions. — Diam. maj. 5^-, min. 5, alt. 3 mill. 



Habitat. — Tahaa. 



Shell depressed, rather thin and dull, obliquely, find}'' and 

 irregularly roughly striate ; spire depressedly conoidal ; whorls 

 5, flatly convex, the last depressed and ribbed ; carinate on the 

 periphery ; aperture triangularly lunate ; peristome simple, 

 acute, slightly reflected, acutely angulate at base and slightly 

 eraargin:ite, continued over base by a callosity ; columella region 

 covered with a copious, depressed subgranulose callosity, which 

 is margined on its outer edge by a groove. Color reddish, some- 

 times of" a straw or horn color. 



Remarhs. — The above species, together with our MSS. faha 

 and tenuiscula, have been referred, by Mr. Cuming, to albo- 

 lahris, Horn, and Jacq. The latter, tenuiscula, is, without 

 doubt, the albolabris, having been collected at the same island, 

 and agrees with the description of that species. 



The above is, however, distinct, and the faba is an analogous 

 form, inhabiting a neighboring island. 



Helicina Oceanica, Pease. 



Description. — T. parva, tenuiscula, nitida, depressa; spira 

 vix elevata, plano-convexa, oblique subtilissime striata ; anfr. 

 4-5, ultimus ad peripheriam acute carinatus, umbilicum callo 

 induta, suleo marginatum ; apertura lunaris ; labro, simplici 

 acuto ; flavescens aut albicans, utrinque lineis aut fasciis undu- 

 latis rufo-fuscis vel fuscis radiatim ornata. 



Dimeusioiis. — Diam. 3, alt. 1]- mill. 



Habitat. — Ins. Kingsmill. 



Shell small, thin, shining, depressed ; spire scarcely elevated, 

 planely convex, obliquely, very minutely striate ; whorls 4 or 



