UTRICULUS. 219 



it is nlso 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- 

 iair sand and mud taken from the stomachs of haddock in the 

 spring of 1842. It is scarce and difficult to obtain {Mig-Iiels}. 

 Casco Bay {^lig-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 whorls. 



Vohmria canaliculata, Say, Jonrn. Acad. Nat. Sc. v. 211 (1822) ; ed. Binvey, 121. 

 Bullina canaUciilata, Say, Amcr. Conch, pi. 19 (1832); ed. Bixney, 193, pi. 39. 

 Bulla canaliculata, Gould, Inv. 166, fig. 97. — De Kay, 19, pi. STi, fig. 328. 

 Bulla obsiricta, Gould, Sdlim. Joiirn. 1st series, xxxviii. 196 (1840) ; Inv. 167, fig. 96. — 



De Kay, X. Y. Moll. 1.5, pi. 5, fig. 102. 

 Utficuhis canaUculatus, 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 

 shallow, rounded groove ; outer lip arching forwards ; inner 

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

 gle oblique fold near the base. 



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

 ters of Massachusetts. This was discovered, among other 

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

 Adams found them in considerable numbers in New Bedford Har- 

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

 lei/) ; South Carolina (^Sa//^. 



Bulla obstricta, now considered a synonyme, was thus described 

 in the first edition : — 



Bulla obsti-icta. 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 liorn-color ; whorls five, the last nearly involving the others, somewh it girt in at 

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

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

 parently double in old sjjccimcns, or rather, a narrow and deep line revolving on the 

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

 behind, widening before ; outer lip sliarp, entire, joining the preceding whorl by a gradual 

 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. 



