BULIMULUS. 243 
millim. in breadth ; the proportion of the diameter to the length in the same specimen 
varies from 1: 148; to 1:12; the aperture occupies in all specimens nearly one half of 
the whole length of the shell. Ina few specimens the uppermost whorls are marbled 
with diaphanous grey and opaque white; all the others are unicolorous white. 
The specimens from Durango are somewhat more oval than conical, smoother, 
and not purely white, but marked with very pale brownish stripes; they have the 
interior of the aperture very vividly brown. By these characters they form a transition 
to B. alternatus; but they are entirely without the columellar tubercle of that species. 
Two others, resembling these but rather larger, collected also by Hoge, are simply 
labelled “ Mexico,” without more definite locality; one of them is figured (fig. 18). 
The figures 20-22 are taken from deformed examples, fig. 23 from a young one. 
2. Bulimulus alternatus. (Tab. XV. figg. 24-26.) 
Bulimus aliernatus, Say, New Harmony Disseminator, Dec. 1830, p. 25 (ed. Binney, p. 39)'; Pfr. 
Monogr. Helic. Vivent. ii. p. 221°; Binney, Terr. air-breath. Moll. of N. Am. iv. p. 126, 
t. 80. figg. 1, 3 (copy of Say’s drawing) °. 
Thaumastus alternatus, Tryon, Am. Journ. Conch. iii. p. 171, t. 9 (18). fig. 6, t. 10 (14). fig. 10°. 
Bulimulus alternatus, Binney & Bland, Land and Fresh-water Shells of N. Am.i. pp. 200-204, 
figg. 347-350, 351 (radula) °; Binney, Terr. air-breath. Moll. of N. Am. v. pp. 388-391 
(with the same figures repeated)*; Cockerell, Journ. de Conch. xxxix. p. 23 (1891)’; 
Stearns, in Proc. Un. St. Nat. Mus. xiv. p. 99 (1891) °. 
Bulimulus (Thaumastus) alternatus, Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 561, 
t. 24. fig. 1 (copy of Say’s original drawing)’; Bland & Binney, Am. Journ. Conch. vii. 
p. 181”. 
Bulimus lactarius (Menke), Pfr. Symb. Hist. Helic. iii. p. 85 (1846); Pfr. Monogr. Helic. 
Vivent. ii. p. 187’; Reeve, Conch. Icon. v., Bulimus, t. 37. fig. 217”. 
Bulimus (Scutalus) marie, Albers, Die Helic. ed. 1, pp. 160, 162”. 
Bulimus marie, Pfr. Monogr. Helic. Vivent. iii. p. 350"; in Martini & Chemnitz, Syst. Conch.- 
Cab., ed. 2, Bulimus, p. 157, t. 48. figg. 7,8; P. Z. S. 1858, p. 23". 
Bulimus (Ena) marie, Pfr. in Malak. Blatt. xii. p. 154 (1855) ”. 
Orthalicus (Scutalus) marie, H. & A. Adams, Gen. Moll. ii. p. 158 , 
Bulimulus (Thaumastus) maria, v. Mart. in Albers’s Die Helic. ed. 2, p. 215”. 
Thaumastus marie, Tryon, Am. Journ. Conch. iii. p. 172, t. 10 (14). fig. 3”. 
Bulimus dealbatus, var., Binney, Terr. air-breath. Moll. of N. Am. ii. p. 276, t. 51a (uppermost and 
lowest figures), t. 5 5 (the three middle figures) *. 
Had. Norva America: Louisiana®7; Texas‘ ® 8 17 20 21, especially at Leon® and San 
Pedro®; Tableland west of Fort Clark® (on the Rio San Pedro, near the frontier 
of the Mexican State of Coahuila). 
N.E. Maxico: State of Tamaulipas®, especially at Matamoros ®, found in great 
numbers on bushes ® (Cowch). | 
1S.W. Mexico: Isthmus of Tehuantepec ° 1°. 
Mexico, without nearer indication of locality * °. 
31* 
