228 AMERICAN JOURNAL 



Shell sublenticular, depressed, rather thin, closely radiately 

 ribbed, on the base ribs rather more close and smaller ; tessel- 

 lated above Avith reddish chestnut and yellowish ; base reddish 

 chestnut, sometimes radiately striped with reddish chestnut ; 

 openly umbilicate ; wdiorls 5, convex, sutures impressed, whorls 

 occasionally slightly angulated at their edge ; last whorl slightly 

 depressed above ; in the middle, at the umbilicus, and on the 

 periphery rounded ; aperture roundly lunate, furnished with a 

 single lamina, revolving within ; lip simple, acute. 



Bemarks. — Allied to H. radieUa, Pfr., inhabiting the Island 

 of Rapa, Austral Group. 



Nanina verticillata. Pease. 



Description. — T. orbicularis, tenuis, fragilis, lucida, pallide 

 fusco-cornea, imperforata ; spira vix elevata ; anfr. 5, convexis, 

 conferte marginatis, sutura impressa; anfr. ultimo ad peri- 

 pheriam rotundato, i;i foveam centralem devexo ; apertura 

 transversalis, semilunaris ; labro simplici tenui. 



Dimensions. — Diam. 6, alt. 4 mill. 



Habitat. — Moorea. 



Shell orbicular, thin, glassy, fragile, shining, light brownish 

 horn color, imperforate, slightly indented at the umbilical 

 region ; spire slightly elevated, obtuse ; whorls 5, convex, nar- 

 rowly margicate, the last rounded at periphery, sutures im- 

 pressed ; aperture transverse, semilunar, lip thin, simple. 



Remarks. — The above differs in several respects from H. 

 brunnea, Anton, to which species it was referred by Mr. Cuming. 



It belongs to the Nanina family in common with all the small 

 glassy species inhabiting Polynesia. The animal of the above is 

 pale, with stout blackish tentacles, foot narrow, rounded behind, 

 and during locomotion does not project beyond the shell. Mucus 

 papilla conical. 



Helicina flavescens, Pease. — Plate 15, fig. 25. 



Description. — T. depresse conoidea, subsemiglobosa, soli da, 

 sublente concentrice striata, distantioribus brevissimse pilosis 

 munita, straminea ; spira obtusa ; anfr. 4, convexiusculi, ultimus 

 ad peripheriam carinatus, infra marginatus, basi convexus ; colu- 

 mella smiplex, callum albidum, circumscriptum retrorsum emit- 

 tens ; perist simplex, brevissime reflexiusculum, crassiusculum ; 

 apertura late semilunaris, subtriangularis. 



Dimensions. — Diam. 6, alt. 3 mill. 



Habitat. — In Insula Mangaia. 



