VOLVULA. 233 



Commencing about the middle of the whorl and covering the base 

 there are numerous, fine, punctate, spiral lines, very much crowded 

 anteriorly. Aperture very narrow, expanded anteriorly ; outer lip 

 a little produced at the top, bending round somewhat abruptly, then 

 following the outline of the body-whorl, and joining the inner lip in 

 a regular curve ; inner lip much thickened at its base, with a 

 minute umbilical chink behind it. Color yellowish-white. (Bush). 



Alt. 3, diam. 1-5 mill. (Bush). 



Cape Hatteras, N. (?., rare in 15-43 fms. (U .8. F. C.), Fernandina 

 Florida. 



Cylichna ccelata BUSH, Trans. Conn. Acad., vi, p. 468, pi. 45, 

 f. 15. Retusa ccelata DALL, Blake Gastr., p. 45. 



Genus VOLVULA A. Adams, 1850. 



Volvula A. AD. in Sowerby's Thesaurus Conchyliorum, ii, p. 558. 

 Not Volvulus Oken, Lehrb. Naturg., 1815 (Moll.), nor of Brulle, 

 Hist. Nat. Ins., 1835, (Coleoptera). Volvulella R. B. NEWTON, 

 Syst. List Edwards Coll. Brit. Oligocene and Eocene Moll., p. 268, 

 1891. WRhizorus MONTF., Conch. Syst., ii, p. 338, 1810. 



Shell external, subcylindrical or long-oval, tapering at both ends, 

 the body-whorl more or less produced in a beak or spine above. 

 Spire concealed ; apsrture as long as the shell, very narrow, the 

 outer lip simple, produced above ; columella somewhat thickened, 

 with the trace of a fold. Type V. acuminata. 



Animal with a squarish frontal disc, produced in two processes 

 behind, as in Retusa, in front of which are the eyes. No epipodial 

 lobes ; foot shorter than the shell, (pi. 60, figs. 9, 10, V- acuminata). 



The shell differs from Tornatina and Retusa in its attenuation at 

 the ends, the upper extremity of the body-whorl being produced 

 into a sort of spine in the typical species. The animal closely 

 resembles Retusa in external features, but it is not known whether 

 radula-teeth are present or not. 



The generic term Volvula is not preoccupied. The names Vol- 

 vulus of Okeu, and Volvulus of Brulle seem to be sufficiently dis- 

 tinct in form to preclude any danger of confusion with Volvula. 



V. SMITHII Pilsbry, n. n. PI. 26, fig. 65. 



Shell minute, elongate-ovate, rostrate above, polished, white, 

 transversely striated at both ends, smooth in the middle ; aperture 



