ACADEMY OF SCIENCES. 201 



Descriptions of New Species of Shells from the South Sea 



Islands. 



BY ANDREW GARRITT, OF TAHITI. 



Genus Mitra Lam. 

 MiTRA (Costeli.aria) crispa, Grt. 



Shell oblong, sub-fusiform, solid ; somewhat shining ; bluish ash or yellowish 

 ash ; spire turretecl, acute ; half the length of the shell ; whorls seven or eight ; 

 flattened, angularly shouldered above; longitudinally-ribbed ; ribs large, slightly 

 angular, intersected by small, flattened, transverse, more or less waved ridges ; 

 base contracted ; aperture white or flesh color ; fauces elegantly lyrate ; col- 

 umella violet, with four or five plaits. 



Length, sixteen mill. 



Habitat, Samoa and Viti Islands. 



A rare species, found in sandy mud, in the upper region of the laminarian 

 zone. Its pale color, violet columella and crisp-like surface, are its most obvious 

 characters. 



Genus Gibbcla, Risso. 



GiBBULA AFFINIS, Grt. 



Shell small, globosely conical, cinereous, articulated by transverse series of 

 small, sub-quadrate, slate-colored spots; whorls five, flattened, last one gibbose, 

 spirally ridged, ridges small — the one on the periphery the larger and more re* 

 mote than the others, and the whole surface decussated with fine, elevated striiE ; 

 base convex ; umbilicus small, crenulate and spirally grooved within ; aperture 

 rounded, with a slight angle at the columella, and pearly within ; outer lip 

 thickened and crenulate. 



Height, five mill ; diameter, six mill. 



Habitat, Yiti and Samoa Islands. 



Not uncommon under stones or reefs, and often found associated with Gih- 

 bula concinna, Dkr., which it closely resembles in shape. The latter species is 

 girdled by beaded ridges, and has a smaller umbilicus than our species. 



GiBBULA FILOSA, Grt. 



Shell small, depressly globose, conical, ashy-white or tawny-yellow, apex rose- 

 color, and the whole surface with revolving brownish lines ; whorls five, convex, 

 the last gibbose ; spirallj'-ridged, ridges flattened, and the whole surface with 

 fine raised spiral striae ; base flattened convex ; umbilicus small, spirally-grooved 

 within ; aperture roundly sub-quadrate, pearly white ; peristome thickened and 

 crenulate on the inner edge. 



Height, five ; diameter, seven mill. 



Habitat, Yiti and Samoa Islands. 



More rare than the preceding species, and inhabiting the same station. 



GiBBULA STRIATA, Grt. 



Shell small, rather thin, globosely conical, grayish-brown, rarely crimson, del- 



