PACHYCHILUS. 453 
B. Subgen. Pacuycui.vs, s. str. 
Sect. Pachychilus, s. strict., and Cercimelania, Fischer & Crosse, Miss. Scient. Mex., Moll. ii. 
pp. 327, 328, 340. 
Conical-oblong, less elongate, smooth (P. apis excepted) ; last whorl comparatively 
large, upper whorls generally much eroded ; peristome thick, simple. 
The two subgenera proposed by Fischer and Crosse under the above names are best 
treated as one, as there is no important difference between them. 
Kegxic, in Greek, the shuttle in the weaving-loom. 
7. Pachychilus liebmanni. (Tab. XXVII. figg. 1, 2.) 
Melania lebmanni, Philippi, Abbild. neuer Conch. iii. p. 58, t. 5. fig. 8 (1848)*; Reeve, Conch. 
Icon. xii., Melania, t. 20. fig. 189°; Brot, in Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, 
Melaniaceen, p. 48, t. 6. fig: 1°. 
Pachychilus liebmanni, Fisch, & Crosse, Miss. Scient. Mex., Moll. ii. p. 347 *. 
Of rather oblong form and considerable size; whorls feebly convex, the upper ones generally much eroded, the 
apex thus being very blunt. Specimens with only four whorls left reach a length of 40 millim., diam. of 
their last whorl 18, aperture 19 high and 11 broad. Philippi’s original figure measures : long. 39, diam. 17, 
length of aperture 18 millim. 
Hab. E. Mexico: Playa Vicente, State of Vera Cruz (Hége); Mexico, without nearer 
indication of locality (Liebmann ! ). 
Brot ® adds also Tehuantepec ” (Geale) as locality ; it is uncertain, however, whether 
the Isthmus or the city of that name is intended. 
Var. gracilior, n. 
Melania gassiesi (Reeve), Gassies, Faune Conch. terr. et fluv. d’ile Nouvelle Caiédonie, i. p. 93 
(1863) °; Brot, loc. cit. p. 47, t. 5. fig. 12°. 
Pachychilus gassiesi, Fisch. & Crosse, loc. cit. p. 348, t. 51. fig. 57. 
Melania sallei, in litt. (Brot) *. 
Distinctly more slender than the typical P. ebmanni. 
a. Long. 42, diam. 17; apert. long. 16 millim. (Brot). Anfr. superst. 4. 
b. ” 31, ” 143 > 29 14 ” 9 3. 
Hab. S.E. Mexico: Rio Teotalcingo, State of Oaxaca (Sallé® 7). 
Dr. Seler informs me that this river is situated in the North-eastern part of the State 
of Oaxaca, and that its waters enter the Rio Colorado, which discharges into the Rio 
Papaloapan, and therefore into the Atlantic ; Teotalcingo is situated in the region of 
coffee-culture. 
