SCALARIANA. MOLLUSCA. SKENEA. 247 



about one fourth of an inch. It is very seldom that one specimen 

 is found by itself ; numbers are usually grouped and intertwined 

 with each other. 



A very fine group was hooked up by a friend in New Bedford 

 harbour, containing not less than fifty individuals, inseparably in- 

 tertwined. The living animals then occupied them. Professor 

 Adams has also found small ones in the same region. Several 

 specimens of Cum'tngia telUnoides were entangled within the folds, 

 and in one of the tubes was a Crepldula plana. In the case of 

 this shell we have the paradox of the apex or commencement of 

 the shell being situated beneath the base. 



Ge.xus SKENEA, Fleming. 



Shell viinule, discoidal; ichorls feic, and destitute of spines ; 

 aperture dilated ; operculum horny. 



Ske'nea serpuloides. 



Shell minute, discoidal, concavely umbilicated beneath, horn- 

 colored, whorls three, mouth expanded. 



Figure IS9. 



State Coll., No. 55. Soc. Cab., No. 2411. 



Helix serpuloides, Montagu ; Test. Brit., SupjiL, 147, p\. 21, f. 3. Dillwyn ; 



Cutal., ii. 884. 

 Turbo serpuloides, Turton ; Couch Diet., 228. Wood ; Index, pi. 32, f. 165. 

 Delphinula ? serpuloides, Adaais ; Bost. Juurn. JVat. Hist., iii. 334. 

 Delphinoidea serpuloidea, Bkown ; Conch, of Great Brit., Sfc, pi. 51, f. 40, 41. 

 Skenea serpuloides, Fleming ; Brit. Anim., 313. 



Shell minute, flat, slightly convex above, and broadly concave 

 below, forming a deep umbilicus, which displays all the whorls 

 within ; whorls three, smooth, a little depressed, light horn-color ; 

 apex scarcely elevated ; suture channelled ; aperture turning 

 downwards, circular, somewhat trumpet-shaped, in contact with, 

 but not embracing any part of, the preceding whorl ; lip sharp, 

 and receding so as to form an acute gap as it joins the preceding 

 whorl ; operculum horny, multi-spiral, the apex central. Breadth 

 2V inch, height 3^ inch. 



Clings to stones lying about low-water mark. I have found it 



