RINGICULA. 401 



Cape Verde Islands, which is like in general aspect, is a much 

 smaller, thicker and more spiralled shell, with a less tumid body- 

 whorl and more regularly conical spire, the slope of the whorls being 

 more flattened ; the apex, too, is much finer. Ringicula semistriata 

 d'Orb., from Cuba, is shorter, broader, and less spiralled. Ringicula 

 auriculata Menard, which is, perhaps, as like as any, has not the 

 contracted base, and its extreme tip is 0"004 in. broad, while here 

 the tip is 0*008 in., or twice as much. I have called this species 

 peracuta, because, though certainly not very sharp, it is much more 

 so than Ringicula acuta Phil. {Wats.). 



R. CABRAi Morlet. PI. 46, figs. 47, 48. 



Shell very minute, subventricose, thick ; whorls 4t, slightly con- 

 vex, separated by a channelled suture, ornamented with deep spiral 

 sulci ; sometimes with a groove above and several on the base, some- 

 times with equally spaced grooves over the whole surface ; last whorl 

 three-fifths the total length. Aperture large, the margins joined by 

 a thick callus ; columella margin strongly arcuate, bearing three 

 minute folds, the upper folds very thick, lower folds delicate and 

 horizontal ; lip arcuate, thick, prominent outwardly, inside with a 

 flat median callus and a small tooth below. Alt. 2*5, diam. 1*8 mill. 

 (il/or/.). 



Island of St. Martha, Columbia. 



R. cabrai MoRL., Journ. de Conch., 1882, pp. 201, 326, pi. 9, f. 1. 



Resembles R. goujoni in the lower lip-tooth, but is smaller, with 

 another style of sculpture and with heavier callus and stronger teeth. 



West African species. 

 R. suTURALis Smith. PI. 46, fig. 57. 



Shell ovate, white, polished ; spire acuminate, suture encircled by 

 a callus cord ; whorls 5, convex, spirally sulcate ; last whorl having 

 10 sulci. Aperture pyriform ; columella callous, triplicate; lip 

 strongly calloused outside. Alt. 2|, diam. nearly 2 mill. (<S.). 



Whydah, W. Africa. 



R. suturalis E. A. S., P. Z. S., 1871, p. 733, pi. 75, f. 12. 



This minute species belongs to the same striated group as R. pro- 

 pinqtians Hinds, from the Philippines and R. someri De Folin, from 

 the Cape Verde Islands. Its much smaller size, the number and 

 position of the teeth, and the callous chord around the suture of the 

 whorls well distinguish it (S.). 



