286 GASTEROPODES. 



The paucity of these parts, however, only shew the earlier stage of the 

 specimen, as the branchiae are of successive evolution with age and 

 dimensions, while they attain greater perfection of form. Those of the 

 second or third pair are the longest, the rest diminish gradually towards 

 the extremity of the animal. 



At first sight the branchial tuft bears considerable resemblance to a 

 fir cone. It consists of a series of prolonged prominences, arranged in 

 circumferential stages. About twelve such stages constituted the largest 

 tuft. Fig. 4. The colours of the branchiae commonly correspond with 

 that of the body, but darker. The first specimen above referred to was 

 white, smooth, the surface much like sheep-skin leather ; the branchiae 

 pale purple. Many specimens are white, which is perhaps converted to 

 brown, as the tips of the branchiae have been observed darkening. 



No eyes have been discovered, though the white or fair colour of 

 subjects might favour their detection. 



The orifice of the oviduct is under the root of the right tuft of the 

 first pair of branchiae. Specimens appear quite turgid with spawn, at 

 various seasons, produced alike in July and in January, or at other 

 seasons. It is deposited in the form of a waving ribband, containing 

 numerous milk-white spherical ova, imbedded in albuminous matter. 

 Fig. 5. 



From the quantities of spawn found on the Sertularia (nemertetia), 

 antennina, perhaps the animal feeds on that zoophyte. 



This species is very subject to mutilation of the branchiae. Two 

 specimens, the one with eight pair, the other with six or seven, had lost 

 thirteen tufts between them, in the course of their second night of con- 

 finement ; and, in two more nights, the former had only three tufts of 

 the whole remaining. These organs are regenerated. A smooth white 

 papilla denotes incipient reproduction. Thence some specimens appear 

 deformed, from the disproportionate size and position between the old 

 and the renovating parts ; though all will prove complete and symme- 

 trical ultimately. 



No regularity appears to govern the loss of the branchiae, either in 



