HELICINID&. 273 
beneath; aperture oblique, entire, nearly semicircular; colu- 
mella short, arcuate, dilated backwards into a thin callus; 
peristome white, narrowly expanded. Operculum thin, chest- 
nut-coloured. Height 6, greatest breadth 7, least br. 6 mill. 
Helicina flavida, Menke, Synops. p. 79, ed. li. p. 132; Sow. Thes. 
n. 41, p. 9, t. 3, f. 117, 134; Pfr. Ic. n. 52, p. 42, t.1, £31, 32, 
t. 3, f. 28-30; Pneuwm. Mon. p. 376. 
Helicina Ambieliana, Boissy, in Guérin, Mag. 1835, t. 68; Potiez 
et Mich. Gal. de Douai, i. p. 228, t. 23, f. 1, 2. 
Helicina trossula, Morelet, Test. Noviss. 1. p. 19, n. 44. 
Hab. Cuba; Tobago, Mexico; Peten, Guatemala. 
86. HenicINA PYGM@MA. 
Shell top-shaped, whitish, smooth, striated longitudinally and 
grooved transversely (under a lens); whorls 5-6, convex, last 
a little larger than the rest, the first ones yellowish; aperture 
oblique, small, yellow like the callus of the columella; peri- 
stome solid; apex acute. Height 5, breadth of the base 5 mill. 
(Pot. & Mich.) 
Helicina pygmea, Pot. 5 Mich. Gal. Dowai, i. p. 230, t. 23, f.9, 10; 
Pfr. Pneum. Mon. p. 377. 
Hab. St. Domingo. 
87. HELICINA TROCHULINA. 
Shell conic, thin, smooth, shining, pellucid, yellow; spire regularly 
conic, with the apex pointed; suture slightly bordered; 
whorls 6, scarcely convex, last imperceptibly descending an- 
teriorly, rather flat beneath; aperture oblique, nearly tri- 
angular; columella shortly receding, simple, dilated backwards 
into a very thin callus; peristome thin, very narrowly ex- 
panded, white and somewhat callous within; right margin 
nearly rectilinear, basal margin slightly sinuate, forming a 
rather effused angle with the columella. Height 44, greatest 
breadth 5, least br. 43 mill. 
Helicina trochulina, Orb. Moll. Cub. i. p. 249, t. 20, f. 10-12? 
Sow. Thes. n. 42, p. 9, t. 3, f. 1052 Pfr. Ic. n. 90, p. 66, t. 9, 
f. 34-36; Pnewm. Mon. p. 377. 
Hab. Cuba (Sagra); Portorico (Moritz). 
88. Henicina ANTONI. 
Shell globose-conic, thin, slightly and irregularly wrinkled, some- 
what shining, yellowish-horn-coloured; spire conoidal, blunt ; 
whorls 4, convex, last indistinctly angulated, rather flattened 
beneath, slightly impressed on the centre; aperture oblique, 
semiovate; columella simple, shortly receding, forming an 
