VELUTINA. 471 



at the external bases. The foot is rather long and wide, and 

 when extended, truncate anteriorly, with inconsiderable au- 

 ricles, which in full action disappear ; it then tapers to a 

 blunt terminus. The branchial apparatus consists of two 

 plumes, lying on the left side of the neck ; the one is a pale 

 brown riband of numerous strong striae of vessels, the other is 

 a small, dark, striated leaf, with an apparent division in the 

 centre, caused by the arterial vessel ; it is placed close under 

 the larger mass. The heart and auricle are at the base of 

 the larger leaf; perhaps the greater range may be the mucous 

 fillets common to most or all the Muricida-, but, from the 

 position of the heart, I think both leaves are branchial. The 

 oesophagus is extremely short ; it almost immediately opens 

 into a large oval stomach that is always filled with pulp. 

 The oesophageal cordon consists of two oval yellow ganglia on 

 each side, and one smaller, a little posterior to the others. 

 The verge is yellow, not long, and is a miniature of that 

 organ in Murex undatus, except that it is rather more pointed, 

 and has the orifice at the point instead of a little below it, as 

 in that species. 



The animal inhabits, at Exmouth, the deepest waters of the 

 coralline zone. This is the last genus which, in respect of the 

 shell and animal, cannot be placed in a simple natural series, 

 but must fall therein by a branch. It is not so aberrant as 

 Lamellaria, as here the coriaceous mantle has vanished, and 

 the auriform shell protecting the viscera and branchiae has 

 become external ; nevertheless, by its thick epidermal coat it 

 appears to supply the place of the thick external mantle of 

 Lamellaria. Its place in the natural order is conspicuously 

 marked out by the retractile proboscis as a sequence to the 

 last genus, and it is assigned to the present family as a striking 

 point of transition to the Canalifera. 



V. FLEXILIS, Montagu. 



V.flexilis, Brit. Moll. iii. p. 350, pi. 99. f. 6, 7 ; (animal) pi. O.O. f. 6. 

 This is a Scottish and Hebridean species : it appears to be- 

 long to this genus. For some account of the animal I refer 

 to the ' British Mollusca/ vol. iii. p. 350. 



