MOLLUSCA. . 625 
Helix humboldtiana (p. 147), 
Helix humboldtiana, Stearns, Proc. U.S. Nat. Mus. xiv. p- 96 (1891)*; Ihering, Zeitschr. fiir 
wissensch. Zool. liv. p. 54 (1892) (anatomy) *; Fischer, Journ. de Conch. xlvii. pp. 297-304 
(with anatomical figures) (Dec. 1899) *, 
To the localities given, add :— 
Hab. Texas, Altada, 5000 feet above the sea (W. Lloyd *°), 
Foot of the living animal not provided with a serrated keel as in H. ghiesbreghti and 
H. eximia. The anatomical examination of the species *6 27 shows that it cannot be, 
as suggested by Stearns25, a form of some European Pomatia, introduced by the 
Spaniards into Mexico. 
f. queretaroana. 
Helix (Lysinoé) queretarvana, Dall, Nautilus, xi. p. 73 (1897) *. 
Pale yellow-brown, without banding, with more pointed spire and less depressed apex. 
Diam. 39, alt. 37 millim. 
Hab. Cuntrat Mexico: Pinal de Amoles, Queretaro (Nelson 28), 
21(a). Helix sebastiana. 
Helhz (Lysinoé) sebastiana, Dall, Nautilus, xi. p. 73 (1897) '. 
Of a dark plum hue, which, where covered by the brownish epidermis, appears nearly black, with three whitish 
bands, the undermost at the periphery ; sculpture consisting of irregular minute vermiculations; more 
depressed than H. eaximia, and with 43 whorls only ; aperture ample, produced above, the lip slightly 
thickened, the pillar-lip broadly reflected over a moderate umbilicus. 
Diam. 40, alt. 30 millim. 
Hab. W. Mexico: San Sebastian, Jalisco ( Nelson '). 
Subgen. Oxycuona (p. 152). 
Pilsbry, ‘ Nautilus,’ xi. p. 87 (1897), has found that the typical species of this sub- 
genus, Helix bifasciata, Burrow, from Brazil, agrees in its anatomical characters with 
Otostomus auris-leporis, Brug. It is not likely that the Costa-Rican and Guatemalan — 
forms referred by me to Oxychona, which differ somewhat from H. difasciata in the 
structure of the shell (this not being so very smooth and shining), really belong to the 
Goniognatha, and they will therefore require a new subgeneric name when their 
anatomical characters are made out. In his general classification of the Helicide 
(‘Manual of Conchology,’ (2) ix. p. 189 (1894) |, Pilsbry had treated Oxychona as a distinct 
genus among the “ Belogona Euadenia.” 
Helix adela (p. 158). : 
Helix adela, Biolley, Mol. terr. y fluv. de Costa Rica, p. 10°. 
To the locality given, add :— 
Hab. Cuntrat Costa Rica: Azahar de Cartago, 1500 metres (Biolley 2). 
BIOL. CENTR.-AMER., Terr. and Fluviat. Mollusca, January 1901. 79 
