CYCLOPHORID. 133 
§ 1. Shell keeled, depressed. 
1. CycLostomus CUVIERIANUS. B. M. 
Shell depressed, decussated by close-set longitudinal and more 
crowded spiral lines, grayish-fulvous; spire little raised; whorls 
5-6, the upper ones convex, the following flattened, with one 
lamellar keel, the last one slightly convex above; furnished at 
its periphery with two distant sharp lamellar keels and nume- 
rous sharply-raised spiral ridges round the wide and open um- 
bilicus; aperture oblique, rather circular, fulvous within; peri- 
stome white, broadly expanded, with the margins joined by 
rather thick callus, right margin showing two channels, colu- 
mellar margin dilated and expanded above. Height 32, greatest 
breadth 64, least br. 54 mill. 
Cyclostoma Cuvieriana, Petit, in Revue Zool. 1841, p. 184; Mag. 
Zool. 1842, t. 55. 
Cyclostoma Cuvierianum, fteeve, Conch. Syst. t. 184, f. 14, t. 185, 
f. 24; Sow. Thes. n. 72, p. 115, t. 30, f. 218, 219; Philippi, 
Abbilld. 7. 5, p. 103, t. 1, f: 1; “Pfr. fon. 1, p. 9, t..1, f. 1A 
Tropidophora Cuvieriana, Pfr. in Z. f. M. 1847, p. 106, n. 1; Gray, 
Cat. Cycl. p. 37, n. 1. 
Cyclostomus Ouvierianus, Pfr. Consp. n. 275; Pneum. Mon. p. 189. 
8B. Smaller, with the columellar margin of the peristome much 
dilated over the umbilicus; height 22, greatest breadth 37, 
least br. 32 mill. 
Hab. Madagascar and Nosibé. 
2. CYCLOSTOMUS FORMOSUS. 
Shell depressed trochiform, rather solid, furnished with three 
sharp keels, with the interstices decussated by raised spiral and 
more crowded transverse lines, fulvous-brownish, articulated with 
white on the keels and near the suture; spire stair-like, rather 
acuminate; whorls 5, flattened, the upper with one keel, the 
last one large, crowdedly spirally grooved below the third keel ; 
umbilicus funnel-shaped ; aperture diagonal, rather circular ; 
peristome simple, with the margins joined by a thin emarginate 
callus, right margin expanded, showing two channels, columellar 
margin narrowly reflected. Height 23, greatest breadth 42, 
least br. 34 mill. 
Cyclostoma formosum, Sow. in Proc. Z. S. 1849, p. 15; Moll. t. 2, 
1.9;.9; £fr. Je. ay 220, tae, 5. 1,2; 
Tropidophora carinata var., Gray, Cat. Cycl. p. 38. 
Cyclostomus formosus, Pfr. Consp. n. 276; Pneum. Mon. p. 190. . 
Hab. Madagascar. . 
N 
