CARDIUM. 



narrow, geniculated, and of flesh colour, the result of a deli- 

 cate and easily obliterated epidermis, under which it is pure 

 white ; its length is at least twice that of the shell. There 

 are a pair of semi-oval branchiae on each side, the upper one 

 being as long as the lower, but not half the depth of it ; they 

 are pale brown and well-striated on the outer surface, but less 

 so within ; the palpi are of the same colour, very long, slender, 

 pointed, with decided raised vessels on the inside, though less 

 marked externally. 



We subjoin a separate account of the young shell, which is 

 the C. ciliare of authors, and has been considered as belonging 

 to the C. aculeatum ; but having had opportunities of exami- 

 ning large suites of both species of |th of an inch to 2| inches 

 diameter, we can confidently state that it is the young of 

 this species. 



C. ECHINATUM, JU11. 



C. ciliare, Auctorum ; Brit. Moll, (animal) pi. N. f. 4, as C. echinatum, 

 jun. 



Animal suborbicular ; the specimen examined was fths of 

 an inch diameter, pale yellow ; the mantle is muscular, and 

 coarsely dentated at the edge, which character in a great 

 measure disappears in the older shells ; it is open throughout, 

 forming short tubes, the branchial one having about sixteen 

 short cirrhi and minute red points at the base ; the anal siphon 

 has the usual tubular retractile process and twelve cirrhi, 

 which also have red points at the base ; besides the siphonal 

 cirrhi, there are above and below and on the tubes a few 

 coarser white filaments, which are invariable appendages of 

 all the Car dia. There are on each side the body a pair of 

 pale brown roughly striated suboval branchial laminae, the 

 upper being much narrower than the under ones; the striae 

 are apparent on both surfaces; the corresponding pairs of 

 palpi are long, narrow, subtriangular, pointed, and rather 

 more strongly striated on the inner than on the outer sides ; 

 they are pale brown. The foot is very long, at least double 

 the vertical measure of the shell, subcylindrical, narrow, 

 pointed, angulated, and of a pale flesh colour. 



H 2 



