248 MOLLUSCA. 
the edge, the part enclosed being dotted. The under surface of the 
foot is figured in the Voyage of the Astrolabe, pl. 39, f. 17-19. 
Inhabits the Paumotu Islands, generally. 
Figure 307, the animal, in the posture of motion. 
RicinvuLa CLATHRATA (Lamarck), Anim. sans Vert.,x.49. RrEVE; 
Conch. Icon., f. 9. 
Animat pale beneath, above greenish cinereous, with a marginal 
dotting of brown. ‘Tentacles annulate with brown at the tips. 
Inhabits Raraka, and others of the Paumotu Islands. 
Figure 308, the animal, as in crawling. 
Several other animals of Purpura and Ricinula were figured, but it 
is so difficult to decide upon the shells to which they belong, that it 
has been thought best to omit them. It is worthy of remark, how- 
ever, that in the Ricinuloid species, the colours green and violet enter 
largely, while in the typical Purpure, bright currant-red with pale 
blue is more characteristic. Ricinula seems to be especially a native 
of the low coral islands. 
PLEUROTOMA SEMINIFERA (Gould). 
Testa subulato-turrita, fuscescens, filts deorsum crescentibus cincta: spira 
anfractibus ad duodecim, juata suturam carinatis, deinde excavatis, 
ad medium nodulis obliquis rubris ornatis: apertura angusta, trientes 
duos longitudinis teste adequans ; cauda brevi ; sinu aque lata ac pro- 
funda ; columella rectiuscula ; fauce hvida. 
Pleurotoma seminifera, Goutp ; Proceed. Boston Soc. Nat. Hist., 
iii. 140. May 1849. Expedition Shells, 63. 
SHELL subulate turreted, of a dusky brownish colour, excepting on 
the ribs, where it is bright red; surface covered with delicate, re- 
