238 SMITH : MOLLUSCA OF TRINIDAD. 
by Mr. Bland, shows that the umbilicus is considerably narrower 
in the latter, which isa more compressed shell with a flatter spire. 
I have placed this species in Omphalina, as conchologically 
it 1s not unlike some of the forms belonging to that North 
American group. The animal has not yet been studied. The 
type of Stexofus (preoccupied for a Crustacean), viz., S. cruez- 
tatus Guilding, may also be referable to this genus. The second 
species (.S. “azdus) described by Guilding, appears to be different 
generically, and is now placed in Guppyva. 
8.—Vitrea implicans (Guppy). Pl. VIII, f. 3, 3b. 
Zonites tmplicans Guppy, Journ. of Conch., 1893, vol. vil., 
p: 214; Amer. Journ. Conch: vol vi5 p. 307, plage 
As the figure quoted above is not characteristic, another 
is now given. 
9.—Vitrea umbratilis (Guppy). 
Zonites umbratilis Guppy, Journ. of Conch., 1893, vol. vit, 
p: 214; Amer. Joum: Conch!, vol! vi, p! 3075 pleuyemeee: 
10.—Guppya semen-lini (Moricand). 
felix semen-lini Moricand, Mém. Soc. Phys. Geneve, 1846, 
vol. xi., p. 149, pl. v., f. 17 ; Reeve, Conch. Icon., voliqne 
f, 639%" Preitier, Conch. CabSved™ yp) 457; sp ae 
f. 9-12 ; Tryon, Man. Conch., ser. 2} volim., p. 175,8pln5es 
f. 55-50. 
Flelix cassiguiensis Newcombe, Reeve, Conch. Icon., f. 334a—b. 
Conulus vacans Guppy, Ann. Mag. N. H., 1866, vol. xvii, p. 53. 
Guppva livida (non Guilding) Guppy, Journ. of Conch., 1893, 
vol. vil., p. 215- 
Guppya vacans. Gibbons, Journ. of Conch., 1879, vol. 11., p. 129. 
Hab.: Bahia (Moricand) ; Brazils (Mus. Cuming) ; George- 
town, Demerara (Gibbons) ; Trinidad (Guppy) ; Cassiqui, Cuba 
(Rve.) ; Demerara (Newcombe in mus. Cuming, for Casszgur- 
ensts). 
Mr. Guppy considers his Conwdus vacans synonymous with 
Guilding’s Stenopus Mvidus, but this identification does not 
J.C., viii., July 1896. 
