20 



at tbe outer base of the tentacles. The longest slope and narrowest 

 end is the forepart of the shell. 



Taken alive at the southern extremity of Mindoro, not far from 

 Ylin : in shallovv \vater and on a sandy bottom. 



In Radius or Ovulum Volva the mantle is covered ■with nipple- 

 shaped tubercles, the nipples and areolae of which are dark-coloured. 

 The tubercles extend to the extreniities of the beaks of the sheU. 

 The foot is moderate and folded longitudinallj-. The tentacles are 

 elongate and subulate. Dredged in Ii ve fathoms from a rocky coral 

 bottom on the shores of Basilan. 



The Radius is slovv and languid in its movements, sliding along 

 deliberately, and not more sensible to alarm than Cyprcea or Cal- 

 purnus. 



In the genus Pyriila, Lamk. (Ficula of Swainson), the siphon is 

 elongate, subcylindrical, and produced in front. The head slender ; 

 the tentacles subulate, on the side of the extremity of the head, and 

 separate from one another at their bases. Eyes sessile on the outer 

 side of the base of the tentacles. The mantle is produced on each 

 side into a rounded lobe eąually reflexed on each side of the shell. 

 Tlie foot is very large and expanded ; rounded in front, and rather 

 produced on each side of the anterior margiu, and expanded and 

 broad \vith a small centrai point behind. There is no operculum. 

 The liead is marbled with light violet and the tentacles %vhitc. Six 

 \vhite opake spots are arranged round the upper surface of the edge 

 of the foot. There is another very beautiful species of Ficula with 

 a pink mantle, mottled \vith white and deeper pink, the under sur- 

 face of the foot dark chocolate-colour ■vvith sparse yellow spots. The 

 first-mentioned species is from the w'est coast of Borneo, from seven- 

 teen fathoms, muddy bottom, and the latterfrom thirty-five fathoms 

 in the sea of Mindoro. 



Mr. Gray has observed that Lamarck established bis genus Pyriila 

 on this species, Bulla ficus, Linn., therefore the generic name should 

 be retained for this form of animals, which he regards as an inter- 

 mediate link bet\veen Muricidce and Cypreeida. 



The animals of Ancillaria crawl Avith a sliding motion and with 

 considerable celerity. The specimens we found on the east coast of 

 Africa were of a dirty wlnte colour with duU broAvn blotcbes. When 

 alarmed, the entire animal is retracted within the shell. 



The genus MargineUa has an elongatcd slender tapering siphon, 

 ■with the tentacles also elongate and slender, bearing the eyes at 

 their outer side just above the base. 'l'he foot is large, broad, trun- 

 cated in front, rather acute behind, and extends beyond the shell on 

 all sides. The mantle is thickened, and reflexed partly over the en- 

 tire circumference of the shell. The animal, when roughly handled, 

 retracted itself entireiy into the shell. Dredged up in three fathoms 

 Tvater, sandy bottom, not far from Anger in Java. 



A second species from the east coast of Africa is similar to the 

 former, but the foot is rather more expanded and more rounded be- 

 hind. The left side of the mantle is rather more produced over the 



