571 



Shell ovately cylindrical, rounded above; apex truncated, white, 

 solid, shining, inferiorly transversely striated ; spire depressed, 

 whorls three, rounded, smooth ; aperture narrow, posteriorly pro- 

 duced, rather contracted in the middle, dilated anteriorly, outer 

 lip rather bent in and thickened in the middle ; columella with 

 the fold very distinct. 



Bay of Manilla; clayey mud, three fathoms. Cuming. 



Sub-genus Utri culls. 



27. Bulla pertenuis (pi. cxx. f. 19), Mighels, Bost. Journ. 

 Nat. Hist. vol. ii. p. 346. pi. xvi. f. 3. 



B. testa minuta, cylindracea, albida, fragili, hyalina ; spira, ele- 

 vata, discoidea, anfractibus quatuor, rotundatis, sutura distincta; 

 labro superne recto, infra rotundato ; apertura superne angustata, 

 infra lata. 



Shell small, cylindrical, whitish, fragile, hyaline ; spire elevated, 

 discoidal, whorls four, rounded, suture distinct ; outer lip straight 

 superiorly, rounded inferiorly ; aperture narrow above, wide 

 below. 



Casco Bay, U. S. Mus. Cuming. 



28. Bulla obtusa (pi. cxx. f. 20), Turt., Walk. Test. min. 



f. 61. 



B. testa, subcylindrica, opaca, alba, longitudinaliter rugoso- 

 striata; spira, distincta, elevatiuscula, anfractibus quatuor vel 

 quinque ; apertura angusta, in medio coarctata, antice dilatata ; 

 columella simplici, subincrassata. 



Shell subcylindrical, opake, white, longitudinally rougldy stri- 

 ated ; spire distinct, rather elevated, whorls four or five ; aperture 

 narrow, contracted in the middle, anteriorly dilated; columella 

 simple, rather thickened. 



British Islands. Mus. Cuming. 



29. Bulla pellucida (pi. cxx. f. 21), Brown. B. Candida, 

 Macgill. 



B. testa oblique ovata, parva, pellucida, inflata, laevi, subum- 

 bilicata ; spira distincta, plana, anfractibus tribus, primo mammil- 

 lato ; apertura ampla, postice coarctata, antice dilatata. 



Shell obliquely ovate, small, pellucid, inflated, smooth, subum- 

 bilicated; spire distinct, flat, whorls three, the first mammillated ; 

 aperture wide, posteriorly contracted, anteriorly dilated. 



British Islands. Mus. Cuming. 



4 E 



