OPEAS, WEST AFRICA. 143 



basal lip more flaring than those of Prince Island, but this 

 character is inconstant (Girard). 



8. 0. GREEFFI Girard. PI. 15, figs. 64, 65. 



Shell turriculate, subperforate, thin, subtransparent, a little 

 shining, of a yellowish- white tint ; sculptured with very fine, 

 quite regular and very arcuate strias of growth. Spire com- 

 posed of. 6 nearly flat whorls, separated by a suture which is 

 not much impressed, and is slightly denticulate by the striae ; 

 terminating in an obtuse apex. Last whorl rounded, slightly 

 more than one-third the total length of the shell. Aperture 

 narrow, long oval, slightly oblique. Peristome simple, acute, 

 the margins joined 'by a very feeble callus; the columellar 

 margin straight, reflexed; basal margin a little effuse; outer 

 margin strongly arched forward. Length 6.5, diam. 2.33, 

 aperture 2.5x1 mm. (Girard). 



Prince Island, with 0. crossei; St. Thome at Cafini (New- 

 ton). 



Opeas greeffi GIRARD, Jornal, etc., p. 106, pi. 1, f. 15. 



" This Opeas seems to be diverse from all the species now 

 known, but approaches a new one found 'by Mr. Newton on 

 Anno-Bom. " 



9. 0. HAMONVILLEI (Dautzenberg) . PI. 15, fig. 70. 



Shell narrowly perforate, long-turrited, thin, a little trans- 

 lucent. Spire elevated, quite attenuate at the summit, com- 

 posed of 8 rather convex whorls separated by a well-marked 

 suture. Surface ornamented with very fine longitudinal rib- 

 striae decussated with finer descending [spiral] lines, giving 

 the shell when examined under a lens, a latticed appearance. 

 Aperture oval, long; columella straight, feebly dilated and 

 reflexed. Lip simple and acute. Uniform yellowish white. 

 Length 11, diam. 3, aperture 3.5 x 2 mm. (Dautz.} 



Senegambia: Bakel (Capt. Em. Dorr). 



Stenogyra h., DAUTZ., Mem. Soc. Zool. France iii, 1889, p. 

 130, pi. 1, f. 7a, 7b. 



Remarkable for its spiral striation, which however is very 

 minute. It is more openly perforate than 0. javanicum, and 

 the arcuate stride are not so strong. 



