UNIO. 513 
" 38. Unio berlandieri. 
Unio berlandieri, Tea, Proc. Acad. Phil. ix. p. 101 (1857)'; Journ. Acad. Phil. (2) iv. p. 369, 
t. 65. fig. 194°; Obs. Gen. Unio, viii. p. 51, t. 65. fig. 194°; Sowerby, in Reeve’s Conch. 
Icon. xvi., Unio, t. 28. fig. 108‘; Pilsbry, Nautilus, v. p. 76°; Fisch. & Crosse, Miss. 
Scient. Mex., Moll. ii. p. 584°. 
Much inflated, with very prominent vertices, otherwise similar to the preceding (U. tampicoensis). 
Hab. N.E. Mexico: Matamoros and Tamaulipas (Berlandier !-* 6), 
Also in the Colorado river, near Austin, Texas (Mc Daniel®). 
* 89. Unio alienigenus. (Tab. XXXV. figg. 2, 2a.) 
Unio alienigenus, Crosse & Fisch. Journ. de Conch. xli. p. 294 (1893) '; Miss. Scient. Mex., Moll. 
ii. p. 590, t. 65. figg. 5, 5 a, and t. 66. fig. 3°. 
Elliptic, more inflated and higher in the hinder part; anterior teeth feeble, more or less compressed. 
Inside white or pale yellowish, in some specimens with a few scattered granules. 
a. Long. 82; alt. vert. 51, ale 48, diam. 30 millim. Vertices in 4 long. 
b. 29 673; 99 36, 39 383, 29 27 39 99 3 
Ce 29 593; ” 303, ” 34, ” 24 ” 2” 3 ” 
a. Fischer and Crosse’s type-specimen ; 6 and ¢. Two smaller, but probably full-grown, specimens in the Berlin 
Museum, from Dunker’s collection, the smaller one given by Anthony. 
Hab. FE. Mexico : Coatzocoalcos, State of Vera Cruz (Sallé! 2); Mexico, without nearer 
indication of locality (Parreyss and Anthony, in coll. Dunker). 
The two specimens in the Berlin Museum have scattered granules on the inside, as 
in U. tampicoensis, var. umbrosus, but they are absent in Fischer and Crosse’s types. 
* 40. Unio sapotalensis. 
Unio sapotalensis, Lea, Proc. Am. Phil. Soc. ii. p. 30 (1841) *; Trans. Am. Phil. Soc. (2) vii. 
p. 283, t. 21. fig. 47°; Obs. Gen. Unio, iii, p. 71, t. 17. fig. 47°; Chenu, Illustr. Conch. 
t. 33. fig. 4; Sowerby, in Reeve’s Conch. Icon. xvi., Unio, t. 91. fig. 495 (copied from Lea)’ ; 
Fisch. & Crosse, Miss. Scient. Mex., Moll. ii. p. 600°. 
Hab. E. Mexico: Rio Sapotal, near Tlacotalpam, State of Vera Cruz (Dr. 
Burrough +-®). 
Conspicuous on account of its numerous dark green rays. 
41. Unio computatus, os 
Unio computatus, Crosse & Fisch. Journ. de Conch. xli. p. 295 (1893) *; Miss. Scient. Mex., Moll. 
ii. p. 601, t. 67. figg. 2, 24 - 
Hab. E. Mexico: near Coatzocoalcos, State of Vera Cruz (Sallé 
Perhaps a variety of the preceding, from which it differs in the larger size, the more 
shell, and the more feeble cardinal teeth. 
1 2). 
swollen 
BIOL, CENTR.-AMER., Terr. and Fluviat. Mollusca, April 1900. 
65 
