234 VOLVULA. 



narrow above, dilated below ; coluraella thick. Alt. 5, diam. 3 milL 

 (&), 



Whydah, W. Africa. 



Volvula cylindrica E. A. SMITH, P. Z. S., 1871, p. 738, pi. 75, f. 

 29. Not V. cylindrica Cpr. 



Peculiar for the beaked apex and the (about 12) spiral striae at 

 the upper and lower portions. ($.). 



V. ACUMINATA Bruguiere. PL 26, figs. 61, 62 ; pi. 60, figs. 9, 10. 



Shell oval-cylindrical, elongated, about three times as high as 

 wide, convoluted, acuminate at the summit, rounded at base, the 

 spire concealed. Thin, translucent and shining, with very weak 

 spiral striae toward the summit and the base. Aperture very nar- 

 row, nearly linear, wider at base ; lip simple and sharp, flexuous, 

 rounded at base ; columellar margin rounded. Columella visibly 

 twisted, arcuate and thickened. Color hyaline white. Alt. 2'7, 

 diam. 1 mill. ; sometimes larger. 



Mediterranean and Adriatic Seas, Atlantic from Norway to the 

 Gulf of Gascony, laminarian and coralline zones ; Gulf of Suez 

 (Cooke). 



Bulla acuminata BRUG., Encycl. Meth., i, p. 376, 1792. 

 PHIL., Enum. Moll, Sicil. i, p. 122, pi. 8, f. 18. Volvula acumi- 

 nata A. AD., Thes. Conch., ii, p. 596, pi. 125, f. 152. BUQ. DAUTZ 

 & DOLLF., Moll. Rouss., p. 534, pi. 64, f. 4, 5. COOKE, Ann. Mag. 

 (5), xvii, p. 130. M. SARS, Bidrag til Kundskab om Christian- 

 iafjordens Fauna, 1870, p. 62, pi. 11, f. 19-22 (living animal). 

 Ovula acuminata FORBES & HANLEY, Hist. Brit. Moll., iii, p. 500* 

 pi. 164B, f. 3. Cylichna acuminata JEFFR., Brit. Conch., iv, p. 411; 

 v, p. 222, pi. 93, f. 1 ; Ann. Mag. Nat. Hist. (4), v, p. 448. Bulla 

 fucicola CHIEREGHINI, BRUSINA, Bib. Malac., ii, Ipsa Chier.C onch., 

 p. 117, 1870, (no description). 



There can be no doubt that the slender Volvula of the Mediter- 

 ranean is the type of Bruguiere's description ; his measurements 

 corresponding closely to specimens, which are about three times as 

 long as wide. His reference to Plancus (De Conchis minus notis, 

 etc.) is less happy, for the figures cited can hardly be believed to be 

 this shell. Whether V. oxytata Bush and V. persimilis Morch are 

 the same f do not know, as I have not seen specimens of them ; but 

 there is nothing in the descriptions, so far as I can see, to distinguish 

 the American forms from the Mediterranean. Chiereghini's B* 



