CYCLOPHORID&. 93 
tinuous, scarcely prominent, outer edge dilated, expanded into 
the plane of the aperture, cut out above the perforation. 
Length 24, breadth 8 mill. 
Cyclostoma Guatemalense, Pfr. in Proc. Z. S. 1851; Jc. n. 257, 
t. 36, f. 13, 14. 
Megalomastoma Guatemalense, Pfr. Consp. n. 193, p. 58; Pneum. 
Mon. p. 132. 
Hab. Guatemala, the province Vera Paza. 
14. MEGALOMASTOMA ALTUM. B. M. 
Shell subperforate, oblong-turreted, rather solid, minutely striate, 
nearly smooth, silk-shining, chestnut-coloured; spire turreted, 
with the outlines curvilinear, with the apex rather pointed, 
yellowish ; whorls 7-8, the upper ones scarcely convex, the 
peuultimate more rounded, last whorl narrower, rounded be- 
neath, with a blunt thread-like keel; aperture rather oblique, 
produced with its base, circular, brown inside; peristome double ; 
inner edge continuous, expanded, with a slightly-impressed 
channel on the left side near the columella ; outer edge shortly 
expanded, dilated above and on the left side. Length 26, 
breadth 9 mill. 
Cyclostoma altum, Sow. in Proc. Z. S. 1842, p. 84; Thes. n. 173, 
p. 152, t. 28, f. 187; Pfr. Ic. n. 131, p. 127, t. 15, f. 12-14. 
Megalomastoma altum, Pfr. in Z. f. M/. 1847, p. 109, n.1; Consp, 
n. 194; Gray, Cat. Cycl. p. 31, u.2; Pfr. Pneum. Mon. p. 182. 
Hab. The Philippine Island of Negros (1. Cuming). 
15. MEGALOMASTOMA SECTILABRUM. 
Shell perforate, oblong-turreted, rather solid, very minutely striate, 
opaque, brown; spire turreted, with the apex rather blunt; 
whorls 7, convex, the last slightly receding below the penulti- 
mate, rounded, not thread-keeled beneath; aperture oblique, 
with the base produced beyond the axis, ovate, roundish; peri- 
stome double; inner edge expanded, affixed, slightly effuse on 
the columellar side, outer edge shortly expanded, slightly inter- 
rupted on the penult whorl, dilated above and below the per- 
foration. Length 23, breadth 10 mill. 
Cyclostoma sectilabrum, Gowld, in Bost. Journ. 1844, p. 459, t. 24, 
f.10; Pfr. Ic. n. 178, p. 164, t. 24, £.17, 18, t. 47, f. 11, 12. 
Megalomastoma sectilabrum, Pfr. in Z. f. M. 1847, p. 109, n. 6; 
Consp. n. 195; Pneum. Mon. p. 133. 
Farcimen sectilabrum, Gray, Cat. Cycl. p. 29, n. 3. 
flab. British Burmah, Tavoy. 
