Mollusca of Dominica. 435 



being more keeled, by its pubescence, and by its basal callus 

 and columellar knot. 



19. Helicina rhodostoma^ Gray. 

 A handsome species, variable as to colour, often nearly 

 white. The expanded peristome varies from white, through 

 orange and red, to a deep chestnut. The operculum of all my 

 specimens is large, thin, and horn-coloured. The spine at the 

 base of the columella is also of variable length, and sometimes 

 it is obsolete, 



20. Helicina conuloides, n. sp. 

 Testa conica, trochiformis, tenuis, Isevis, nitens, diaphana, rubro- 

 brunnea ; spira conica, elevata ; apex acuminatus ; anfr. (J, vix 

 convexi ; apertura leviter obliqua ; peristoma tenue, rectum ; co- 

 lumella in callum albidum et circumscriptum dilatata. 

 Alt. 4 millim., lat. 5|, 

 Operculum tenue, diaphanum, margine interno paulo incrassato. 



A conic-trochiform, thin, smooth, shining, diaphanous, 

 reddish-brown Helicina, with an elevated conic spire and a 

 pointed apex ; whorls 6, scarcely convex ; aperture slightly 

 oblique ; peristome thin, straight ; columella dilated into a 

 whitish, rather circumscribed, not very large callus. Oper- 

 culum thin, diaphanous, somewhat thickened on the inner 

 margin. 



Allied to H trochulina, D'Orb. (Moll, de Cuba, tab. 20. 

 f. 10-12). It differs in being scarcely so high relatively, in 

 its more pyramidal form, and its thinner peristome, which is 

 not expanded ; its colour, also, is reddish brown, instead of 

 yellow. One of my examples was furnished with two oper- 

 cula. I have named the species from its great resemblance, in 

 colour, shape, and texture, to the shells of the subgenus Co- 

 nulus of Zonites. 



Part II. GRENADA. 



1. Veronicella Icevis, F^r. 

 Vaginulus Sloatiei, F^r. (Guppy). 



2. Conulus vacans, Guppy. 

 It has been suggested to me that this mollusk, which I 

 described as occurring in Trinidad, is possibly the same as 

 Stenopus lividus of Guilding. I had, however, made a careful 

 comparison of Guilding's figure, and it seemed to me that the 

 two were distinct, although there can be little doubt that both 

 mollusks belong to the same group. I venture to think, how- 



