CYCLOPHORIDA. 95 
19. MEGALOMASTOMA ANTILLARUM. B. M. 
Shell shortly rimate, turreted, with crowded longitudinal rib-like 
striz, covered with a slightly shining, horn-coloured-brownish 
periostraca; spire elongate, with the apex rather blunt ; suture 
deep; whorls 8, convex, the last narrower, forming about } of 
the whole length, furnished beneath with a raised, cord-shaped 
keel; aperture somewhat oblique, nearly circular, shining fulvous 
inside; peristome indistinctly double; detached, continuous, 
angulated above; shortly expanded, with the upper left margin 
rather cut out. Length 17, breadth 5$ mill. 
Cyclostoma Antillarum, Sow. Thes. n. 168, p. 150, t. 28, f. 180; 
tse, BD. 159, p. 127, t. 15, £.15,.16. 
Megalomastoma brunnea, Guild. in Swains. Malac. p. 333, f. 97, 
is 2 
Be eiGmastoina suspensum, Gwild. cbid. p. 186, f. 29 ? 
Megalomastoma Antillarum, Pfr. in Z. f. Mf, 1847, p. 109, n. 2; 
Consp. n. 199; Gray, Cat. Cycl. p. 31, n.5; Pfr. Pnewm. Mon. 
p. 135. 
flab. W. Indies, the islands of Tortola and St. Vincent. 
X. CATAULUS. 
Operculum orbicular, flat, horny, many-whorled. Shell perforate, 
pupa-shaped, not callous, furnished with a filiform basal keel; 
aperture entire, prolongated at its base by a rather circular 
channel; peristome continuous, dilated, at its lower extremity, 
into the keel of the last whorl. 
Cataulus, Pfr. in Z. f. Mf. 1851, p. 149; Consp. p. 21, Pneum. Mon. 
~ 136. 
Cyclostoma spec., Avct. 
Megalomastoma spec., Gray. 
1. CATAULUS TORTUOSUS. B. M. 
Shell deeply rimate, fusiform-oblong, rather solid, very minutely 
striate, shining, whitish ; spire ovate-turreted, with the apex 
rather pointed; whorls 7, convex, the two penultimate ones 
broad, last whorl more slender, detached, protracted downward, 
furnished beneath with a thread-shaped keel, which becomes 
broader near the aperture; aperture perpendicular, rather cir- 
cular; peristome continuous, white, reflected, distinctly chan- 
nelled at its base, angulated externally, sinuate on the right 
side. Length 18, breadth 6 mill. 
Turbo tortuosus, Chemn. Conch. Cab. xi. p. 158, t. 195, f. 1882, 1883. 
Helix (Cochlodina ?) tortuosa, Féruss. Prodr. n. 504, p. 61. 
Pupa tortuosa, Gray, in Annals of Phil. new ser. ix. p. 413. 
Urocoptis ? tortuosa, Beck, Ind. p. 83, n. 10. 
