CYCLOTUS. 3 
CYCLOTUS. 
Cyclotus, Guilding, in Swainson’s Malac. p. 186 (1840). 
Operculum thick, calcareous, many-whorled, nucleus central. 
Subgen. APEROSTOMA. 
Aperostoma (Troschel), Pfeiffer, in Malak. Blatt. 1847, p. 47. 
Neocyclotus, Fischer & Crosse, Miss. Scient. Mex., Mollusca, ii. p. 148 (1889). 
Peristome simple, straight. 
1. Cyclotus (Aperostoma) irregularis. 
Cyclostoma (Cyclotus) irregulare, Pfr. P.Z. 8. 1855, p. 117°. 
Cyclotus irregularis, Pfr. Monogr. Pneum. Vivent. ii. p. 15°; Reeve, Conch. Icon. xiv., Cyclotus, 
t. 4. fig. 18°; Angas, P. Z. S. 1879, p. 483°. 
Hab. %. Costa Rica: Costa Rica 23 (Gadd 4; mus. Cuming+); Cache (Rogers); ‘the 
commonest shell in Talamanca; coast region, and to 500 feet high on the hills” 
(Gabdb *). 
Lower margin of the aperture often injured, probably by the “animal grazing, so to 
say, to satisfy a demand for lime”*. From this circumstance it becomes doubtful 
whether C. bisinuatus is really distinct from C. irregularis. 
2. Cyclotus (Aperostoma) bisinuatus. 
Cyclotus bisinuatus, v. Mart. in Malak. Blitt. xi. p. 118, t. 3. figg. 1, 2 (1864) *, & xv. p. 156 (1868) *; 
Pfr. Monogr. Pneum. Vivent. iii. p. 26°. 
Hab. S.W. Guatemata: Costa Cuca above Retalhuleu ; southern slope of “Los Altos,” 
at San Francisco Miramar 2500 feet; and in the district Cholhuitz, on the slope 
of the Volcan de Santa Maria, at an elevation of from 3000 to 5000 feet, in the 
woods on the ground, under decayed leaves (Stol/). 
C. Costa Rica: elevated plains of Costa Rica (C. Hoffman '* and Carmiol?, in mus. 
Berol.). { ye Le) Se 
Outer face of the operculum deepened in the middle; whorls at most six, the inner 
edge of each prominent in a right angle. 
Living animal pale reddish-grey ; feelers bright orange, tapering; muzzle produced, 
bilobed (Séo/@). 
8. Cyclotus (Aperostoma) dysoni. (Tab. I. figg. 1, 2, 17.) 
Cyclostoma dysoni, Pfr. P.Z. 8. 1851, p. 243"; Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, 
Cyclostoma, no. 244, p. 259, t. 35. figg. 5, 6°. 
Cyclophorus dysoni, Pfr. Monogr. Pneum. Vivent. i. p. 98°; Gray, Cat. Phaneropn. p. 69%. 
Cyclotus dysoni, Pfr. Monogr. Pneum. Vivent. ii. p. 19 (operculum) ’; Reeve, Conch. Icon. xiv., 
Cyclotus, t. 6. fig. 31°; v. Mart. P. Z.S. 1875, p. 648"; Angas, P. Z.S. 1879, p. 483°. 
1* 
