234 MOLLUSCA. 
A. typicus: long. 22, diam. et apert. 10 millim. 
a: albidus, fasciis 3-5 pallide fulvis, equalibus. (Fig. 1.) 
(Fisch. & Crosse, loc. cit. t. 21. figg. 4, 4a.) 
6: albidus, fasciis 5 pallide fulvis, fusco-maculatis. (Fig. 3.) 
¢: unicolor, pallide fulvus. (Fig. 2.) 
Hab. Mexico, without nearer indication of locality (UAde '~). 
E. Mexico: Aculcingo, State of Vera Cruz, south of Orizaba (Boucard *). 
W. Mexico: Sayula, State of Jalisco (Hoge). 
B. cuernavacensis : major, fasciis magis distinctis, latiusculis ; long. 29, diam. 15, apert. 13 millim. (Fig. 4.) 
Bulimulus (Scutalus) cuernavacensis, Crosse & Fisch. in Journ. de Conch. xxii. p. 283 (1874) ° 
Fisch. & Crosse, Miss. Scient. Mex., Mollusea, i. p. 582, t. 28. figg. 11, 11 a (young ?) ’. 
_ Bulimus cuernavacensis, Pfr. Monogr. Helie. Vivent. vill. p. 152°. 
Bulimulus cuernavacensis, Strebel, Beitr. Mex. Land- und Sitissw.-Conch. v. p. 65, t. 12. fig. 17°. 
Hab. Centrau Mexico: Cuernavaca (Boucard §"). 
EK. Mexico: Orizaba and Maltrata, a little west of Orizaba (Hoge). 
C. tepicensis: minor, anfractibus superioribus fasciatis, mediis maculatis, ultimo pallido, basi fascia una lata 
diluta ; long. 18, diam. 9, apert. 84 millim. (Fig. 5.) 
Hab. W. Meuxico: Tepic, State of Jalisco (Hoge ®). 
D. borealis: minimus, griseo-albidus, superne seriebus macularum 1-3, inferne fascia una lata pallida ; long. 15, 
diam. 8, apert. 7 millim. (Fig. 6.) 
Hab. N.W. Mexico: Ventanas, State of Durango, at an elevation of 2000 feet above 
the sea (Forrer). 
The first one and a half whorls are unicolorous, yellow, and finely reticulated. The 
typical form may be described as white with fawn-coloured bands, or fawn-coloured with 
white bands: the latter definition is perhaps the best, as the fawn occupies a greater part 
of the surface, and is the only colour present in subvar. c, and I have used it in my 
earlier descriptions!?. But if we examine the var. cwernavacensis, and the majority of 
the other species of this genus, we shall, perhaps, prefer to regard the coloration as 
white with fawn bands; but then we must admit that the uppermost band reaches the 
suture and the lowest one the umbilicus, and that the unicolorous subvariety ¢ is pro- 
duced by all the bands uniting together. The variation in the number of bands is 
caused by the uppermost disappearing, and by the fourth and fifth uniting into one. 
This species, as regards the shell, bears some resemblance to Bulimulus exilis, Gm. 
(guadelupensis, Brug.), the type of the genus Bulimulus; but having examined the 
radula of O. uhdeanus, I have found that it agrees better with that of Otostomus, the 
median tooth being also remarkably smaller than the neighbouring ones. 
