92 CATALOGUH OF PHANEROPNEUMONA. 
1i. MEGALOMASTOMA CHRYSALLIS. 
Shell umbilicate, distortedly ovate, solid, slightly striate and 
foveolate, brownish-flesh-coloured ; spire irregularly ovate, with 
the apex conoidal, rather pointed; suture slight; whorls 6, 
moderately convex, the penultimate rather flattened on the side 
of the mouth, the last narrower; aperture perpendicular, cir- 
cular; peristome thick, dilated, expanded, reflected, with the 
affixed upper margin forming a horizontal line. Length 16, 
breadth 9 mill. 
Cyclostoma chrysallis, Pfr. in Proc. Z. S. 1851; Jc. n. 217, t. 31, 
f, 23, 24. 
Megalomastoma chrysallis, Pfr. Consp. n. 191, p.73; Pnewm. Mon. 
Dp. lol. 
Hab, Ava. 
§ 3. Peristome expanded, rather thin, usually double. 
12. MeGALOMASTOMA SIMULACRUM. 
Shell subperforate, turreted, truncate, solid, smooth, scarcely 
shining, greenish-fulvous or chestnut-coloured; spire elongate, 
tapering gradually; suture slightly bordered; whorls (remain- 
ing) 6, moderately convex, the last one with a thread-like keel 
at its base, striate above the keel; aperture perpendicular, 
rather circular; peristome double; inner edge shortly pro- 
minent ; outer edge broadly expanded, white, concave internally, 
interrupted near the perforation, with the upper margin ap- 
pressed ; columellar margin free. Length 35, breadth 11 mill. 
Cyclostoma simulacrum, Morelet, Test. noviss. p. 22, n. 54; Pfr. Ic. 
n. 256, t. 36, f. 11, 12. 
Megalomastoma simulacrum, Pfr. Consp. n. 192; Pneum. Mon. 
p- 151. 
8. Smaller, with the whorls more convex; length 28, breadth 10 
mill. 
Cyclostoma Copanense, Sow. Thes. Suppl. n. 194, p. 163%, t. 31 B. 
f, 310, 311. 
Hab. Guatemala, the province Vera Paz. 
13. MeGaLoMASTOMA GUATEMALENSE. 
Shell perforate, oblong, rather solid, subtruncate, slightly striate, 
olivaceous-brownish ; spire turreted, with the outlines rather 
curvilinear; whorls 6, little convex, the last narrower, descend- 
ing interiorly and shortly detached, compressed beneath, but not 
keeled round the open perforation ; aperture perpendicular, 
rather circular ; peristome free, white, double ; inner edge con- 
