66 CATALOGUE OF PHANEROPNEUMONA. 
periostraca ; spire somewhat raised, reddish, slightly mucronate ; 
whorls 5-6, moderately convex, the last one somewhat depressed, 
- obsoletely angular at its periphery, convex beneath, and rather 
smooth in the umbilicus, which is very broad ; aperture oblique, 
rather ovate, angular above, pearly inside ; peristome simple, 
straight, with the margins approximate, united by a thin de- 
posit; columellar margin strongly arcuated, rather thickened. 
Operculum yellowish, with the edges of the whorls lamellar, 
fringed. Height 23, greatest breadth 49, least br. 41 mill. 
Cyclostoma Cumingil, Sowerby, in Proc. Z. S. 1832, p. 32; Mill. 
Synops. p. 87; Desh. in Lam. Hist. ed. ult. vii. p. 367, n. 30 ; 
Sow. Spec. Conch. f. 187-189; Reeve, Conch. Syst. t. 185, f.19; 
Sow. Thes. n. 54, p. 108, t. 24, f. 68, 69; Pfr. Lc. n. 89, p. 92, 
t. 12, f. 1-3. 
Cyclostoma striata, Lea, Trans. Am. Phil. Soc. v. t. 19, f. 77. 
Cyclophorus Cumingii, Pfr. in Z. f. Mf. 1847, p. 108, n. 32 ; Consp. 
n. 133; Gray, Cat. Cycl. p. 22, n. 34; Pfr. Preum. Mon. p. 94. 
flab. W. Columbia, the Island of Tumaco (H. Cuming). 
72. CYCLOPHORUS ALTERNANS. 
Shell conoidally depressed, rather thin, sculptured with crowded 
alternatively smaller and stronger sharp ridges, not shining, 
white, with a pale yellowish deciduous periostraca ; spire very 
shortly conoidal, with the apex rather blunt ; suture slightly 
channelled ; whorls 5, moderately convex, last rounded ; umbi- 
licus middle-sized, conic; aperture little oblique, rather cir- 
cular; peristome simple, straight, with a brownish edge, rather 
continuous, with the margins joined on the penult whorl by a 
shining callus. Operculum membranaceous, wax-coloured. 
Height 10, greatest breadth 20, least br. 16 mill. 
Cyclostoma alternans, Pfr. in Proc. Z. 8.1851; Jc. n. 324, t. 41, 
f, 30-82. 
Cyclophorus alternans, Pfr. Consp. n. 134, p. 55; Pnewm. Mon. 
p- 94. 
Hab. Madagascar. 
73. CycLtopHorus BovurRcIERI. 
Shell orbicular, rather conoidal, solid, minutely striate, and sculp- 
tured with more or less crowded, raised, spiral lines, covered with 
a brownish-olivaceous periostraca ; spire shortly conoidal, with 
the apex somewhat nipple-shaped; whorls 43-5, convex, in- 
creasing slowly, last cylindrical, slightly descending anteriorly ; 
umbilicus wide; aperture oblique, roundish, rather angular, 
pearly inside ; peristome simple, straight, shortly affixed to the 
penult whorl. Height 11, greatest breadth, 234, least br. 18 
mill. 
