154: On the Mollusca of Long Island. 



four to ten fatlis. Animal white. Eyes near base of tentacles, 

 prominent. Foot about quarter the length of the shell. Verj 

 active. 



31. Cerithiopsis terehellum Stimpson. Moderately abundant. 

 4 to 10 faths. Yery active. 



32. Ccecum pulchellum Stimpson. Several hundred speci- 

 mens were obtained from the fine sand which passed through 

 the sieve, in examining the refuse of a dredging made several 

 weeks before in ten faths., 6n a bottom of broken shells. Many 

 of them appeared perfectly fresh, and were probably alive 

 when dredged. I have since found it in the fine sand from 

 almost every deep dredging ; though, from its minuteness, I 

 have never succeeding in getting it except from the dried sand, 

 and have consequently been unable to examine the animal, so 

 as to ascertain whether it differs from Mr. Stimpson's species, 

 which he appears to suspect may be the case. 



33. Co&cum Cooperi {n. s.). Two specimens were dredged 

 in four or five faths. sand, in the northern part of Gardiner's 

 Bay. The shell belongs to the section " Elephantulum" of the 

 Genus Ccecum, as divided by Carpenter. It has about twenty- 

 four somewhat rounded longitudinal ribs or lirse, crossed by 

 numerous rings, rather obscure about the middle of the shell, 

 but very distinct at the two extremities, where the longitudinal 

 ribs become indistinct. There is a slight constriction near the 

 mouth of the shell, which swells out again beyond it. Plug 

 mucronate, with the apex inclining to the left, when looking at 

 the back of the shell. The lateral profile is concave, rising 

 rapidly towards the back. Operculum concave. Length .13 in. 

 width in middle .035 in. The shell is white, not very thin, and 

 moderately curved. In possessing both longitudinal ribs and 

 rings this species resembles Coecum {Eleiyhmitulwri) plicatum 

 of Carpenter, from the "West Indies, which, however, is smaller, 

 and appears, by the description, to have a much longer plug, 

 symmetrically placed on the end of the shell. I have named 

 the species in honor of Mr. "Wm. Cooper, of Hoboken, to whose 



