230 MOLLUSCA. 
41. Otostomus discrepans. 
Bulinus discrepans, Sowerby, P. Z. S. 1833, p. 72'; Conch. Ilustr., Bulinus, fig. 52°; Tate, 
Am. Journ. Conch. v. pp. 152, 156 (1870). 
Bulimus (Bulimulus) discrepans, Beck, Index Moll. p. 65°. 
Bulimus discrepans, Deshayes, in Lamarck’s Hist. Nat. des Anim. sans Vert. ed. 2, viil. p. 279 °; 
Pfr. Monogr. Helic. Vivent. ii. p. 176°; Reeve, Conch. Icon. v., Bulimus, t. 23. fig. 146°. 
Bulimus (Mesembrinus) discrepans, Albers, Die Helic. ed. 1, p. 158°; Pfr. in Malak. Blatt. i. 
p. 158 (1855) °. 
Orthalicus (Mesembrinus) discrepans, H. & A. Adams, Gen. Moll. i. p. 157 an 
Bulimulus (Liostracus) discrepans, Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 503 a 
Hab. Cenrrat Guatemata: Salama (Morelet!!) ; San Geronimo near Salama (Champion). 
E. Guatemata: Zacapa, on Cereus sp. (Stol?). 
Satvapor: Conchagua, under the bark of trees (Cuming 1*°"). 
CentraL Nicaragua: Granada, Masapa, San Nicolas, in the Savana-region (Tate *). 
N.W. Costa Rica: Guanacasta, in the Bay of Salinas, in the woods (Pitter). 
The name discrepans refers to the difference in the painting of the upper and 
lower parts of the shell: on the upper part of the last and on the visible part of 
all the preceding whorls are very narrow, but sharply delineated, oblique, dark 
brown stripes, two of which are often nearer to each other; at the base of the 
last whorl, on the contrary, are two spiral dark brown bands, and the space between 
them is sometimes yellow, but often whitish like the rest of the shell. A similar 
discrepancy of the painting is to be seen in the widely remote genus Amphidromus of 
the Malayan Archipelago, where most of the species in their young state, and some 
also in the adult (A. contrarius &c.), have also vertical stripes on the upper and two 
spiral bands on the lower part of the whorls. 
This species has hitherto only been found at a few widely distant localities. 
The specimens from Guanacasta are somewhat smaller than Sowerby’s type, measuring 
only :—long. 16, breadth 8, and aperture 9 millim. 
Jaw and radula examined by myself. 
42. Otostomus alternans. 
Bulinus vexillum, Broderip, P. Z.S. 1832, p. 105°; Sowerby, Conch. Ilustr., Bulinus, fig. 26°. 
Bulimus vexillum, Deshayes, in Lamarck’s Hist. des Anim. sans Vert. ed. 2, viii. p. 272°; Reeve, 
Conch. Icon. v., Bulimus, t. 23. fig. 152 * (nee Wood, 1828). 
Bulimus (Bulimulus) alternans, Beck, Index Moll. p. 65 °, 
Bulimus alternans, Pfr. Monogr. Helic. Vivent. ii. p. 207 °. 
Bulimus (Leptomerus) alternans, Albers, Die Helic. ed. 1, p. 166"; Pfr. in Malak. Blatt. ii. p. 160 
(1855) °. | 
Orthalicus (Leptomerus) alternans, H. & A. Adams, Gen. Moll. ii. p. 156°. 
Bulimulus (Liostracus) alternans, vy. Mart. in Albers’s Die Helic. ed. 2, p. 213*°; Binney, Ann. 
