222 BULLION. 



Found by Professor Adams in the mud of New Bedford Harbor. 

 It was originally found by Colonel Totten in the harbor of New- 

 port. 



Maine (Mig-hcls} ; New Bedford (Stlmpsoti) ; Connecticut (Lins- 

 ley^. Fossil, Montreal (^Dawson) ; Buzzard's Bay, southward 

 (^Stiinpson). 



In solidity, color, polish, and general shape, this is allied to Utric- 

 ulus Gouldil; l)ut is much smaller, and is at once distinguished 

 by its exhibiting no spire. 



Oeniis BUL,L,A, Lin. 1759. 



Eyes conspicuous, sessile on the middle of the frontal disk. Man- 

 tle with the outer margin forming a thick, fleshy lobe. Foot with 

 the lateral lobes moderate, and the hind part not extending beyond 

 the shell. 



Shell convolute, ovate or sub-globose, smooth, mottled ; spire in- 

 volute, sunken, causing the apex to be tuludar or perforate ; aper- 

 ture extending the entire length of the body whorl ; inner lip sim- 

 ple ; columella none ; outer lip acute. 



Bulla incincta. 



Bulla incincta, Mighels, Proc. Bost. Soc. i. 188 (1844). — Stimpson, Check Lists, 4 

 (1860). 



Shell small, cylindrical, opaque, white ; whorls three, the first 

 slightly depressed, the last distinctly girded above the middle ; epi- 

 dermis yellowish ; spire obtuse, elevated ; suture canaliculate ; aper- 

 ture narrow behind, wide and rounded before ; right lip sharp, 

 entire, advanced in the central region, with a fissure posteriorly. 

 Length, three twenty-fifths of an inch ; breadth, three fiftieths of 

 an inch. Casco Bay {Mig-he/s). 



Bulla solitaria. 



Fig. 92. 



Shell oval, bluish-white, fragile, the last whorl enveloping all the others, and 

 covered with minute, regular, revolving lines, with an imperfect opening in the 

 region of the spire. 



Bulla inKculpta, Tottex, Silliman's Jonrn. xxviii. 350, fig. 4. — Gould, Inv. 162, fig. 92. 

 -De Kay, N. Y. Moll. 14, pi. 5, fig. 100. 



