UTRICULUS. 219 



it is also entirely destitute of the revolving lines, which are seen 

 on that shell. It is the smallest species of the genus that has hith- 

 erto been found on the American coast. I first detected it in sift- 

 ino; sand and mud taken from the stomachs of haddock in the 

 spring of 1842. It is scarce and difficult to obtain {Mighe/s}. 

 Casco Bay (^Mig-hcls) ; Cape Cod to Grand Manan (^Slimpson}. 



Utriculus canaliculatus. 



Fig. 97. 



Shell nearly cylindrical, spire somewhat elevated, with a groove on the sum- 

 mit of the Avhorls. 



Vo'varia canal iculata, Sat, Journ. Acad. Nat. Sc. v. 211 (1822) ; ed. Binney, 121. 

 BnlJina canalicidata, Sxy, Amcr. Couch, pi. 19 (1832); ed. Binney, 193, pi. 39. 

 Bulla canalicidata, Goold, Inv. 166, fig. 97. — De Kay, 19, ])1. 3.5, fig. 328. 

 Bulla obslricta, Gould, Sdlim. Journ. 1st series, xxxviii. 196 (1840) ; luv. 167, fig. 96. — 



De Kay, N. Y. Moll. 15, pi. 5, fig. 102. 

 Utriculus canaliculatus, Stimpson, Check Lists, 4. 



Shell cylindrical, white, and shining, with very faint lines of 

 growth ; spire a little elevated, crowned with a minute but promi- 

 nent tip ; whorls about five, the summit of each having a 



Fjcr. 510. 



shallow, rounded groove ; outer lip arching forwards ; inner 

 lip overspread with a thin plate of enamel, and having a sin- 

 gle ol)lique fold near the base. 



I have found only one specimen of this shell from the wa- u. cana- 

 ters of Massachusetts. This was discovered, among other 

 minute shells, in sand lirought from Martha's Vineyard. Prof. 

 Adams found them in consideraljle numbers in New Bedford Har- 

 bor. Massachusetts Bay, southward (^Stimpson) ; Connecticut (Lins- 

 ley^ ; South Carolina (Say). 



Bulla obstricta^ now considered a synonyme, was thus described 

 in the first edition : — 



BuHa ohsfricia. Shell oval-cylindrical, white, nearly smooth, spire somewhat elevated, 

 last whorl nearly as long as the shell, and slightly girted at the middle ; a fold on the 

 pillar. (Fig. 96.) 



Shell small, cylindrical, with each extremity rounded, semi-transparent, opaque white, 

 or pale horn-color ; whorls five, the last nearly involving the others, somewhat girt in at 

 the middle, nearly smooth, covered with a light-yellowish epidermis; spire obtuse, rising 

 above the junction of the lip to about one fifth the length of the shell ; suture deep, ap- 

 parently double in old specimens, or rather, a narrow and deep litie revolving on the 

 shoulder of each whorl, near the suture, forms a sort of channel; aperture very narrow 

 behind, widening before ; outer lip sliai-p, entire, joiniuc: the preceding wh-irl by a grailual 

 approach, and then turning down the inner border in the form of a thick, slightly at- 

 tached plate of enamel ; from the front, as it turns back, it becomes thicker and rounded, 



