534 MOLLUSCA. 
indication of locality is given for them. As all these large-sized Anodonte are rare in 
collections, the range of their individual variation is still unknown. 
12. Anodonta grijalve. 
Anodonta grijalve, Morelet, in Journ. de Conch. xxxii. p. 123 (1884) '; Fisch. & Crosse, Miss. 
Scient. Mex., Moll. ii. p. 331, t. 59. fig. 1 *. 
More elongated than the preceding, low and somewhat produced before, rounded behind; ventral margin 
scarcely arcuated, but with a peculiar prominence somewhat behind the middle; outside dark brown. 
a. Long. 161; alt. vert. 96, alee 70, diam. 95 millim. Vertices in + long. 
b 364, 180; » 110,, ? 4 95 ,, - 2 4 
a. Fischer and Crosse’s figure; 6. Morelet’s measurements. 
Hab. S.E. Mexico: Rio de los Idolos, one of the branches of the Rio Grijalva, State 
of Tabasco (Morelet }?). 
The name Grijalva was given to this river in honour of one of the first Spanish 
discoverers in this part of the world, Juan Grijalva, 1518. 
ScoLIANODON, v. Mart. 
13. Anodonta inzquivalvis. 
Anodonta atrovirens, Philippi, in Zeitschr. f. Malak. v. p. 180 (1848) °. 
Anodonta inequivalva, Lea, Proc. Acad. Phil. 1868 p. 95°; Journ. Acad. Phil. (2) vi. p. 292, t. 43. 
fig. 108°, =Obs. Gen. Unio, xii. p. 52, t. 48. fig. 108 *. 
Anodonta inequalis (Lea), Tate, Am. Journ. of Conch. v. p. 160 (1870) *. 
Oval, fore part somewhat produced, hinder part rather high, angulated, ventral margin rounded. Outside 
dark green or yellowish-green, obscurely radiated; inside bluish-white and very iridescent. 
a. Long. 42; alt. vert. 26, ale 26, diam. 163 millim. Vertices in 3 long. 
b. ” 31; ” 24, 4 2, » 13 9 ” ? ” 
Hab. Centrau Nicaragua: Lake of Nicaragua (Bridges ?~*); Lake Nicaragua, near San 
Ubaldo, Rio Malacotoya (Late *) ; Nicaragua, without nearer indication of locality 
(Largilliert +). 
All the specimens seen by Lea were slightly inequivalve, having the beak of the left 
valve a little higher than that of the right, and having a slight flexure on the superior 
anterior margin. This peculiarity is also visible in some species of Unio from the 
same lake, see antea, pp. 483, 498. 
Var. lenticularis. 
Anodonta lenticularis, Lea, Proc. Acad. Phil. 1868, p. 95°; Journ. Acad. Phil. (2) vi. p. 290, t. 41. 
fig. 102 7, =Obs. Gen. Unio, xii. p. 50, t. 41. fig. 102°. 
Comparatively higher and more circular than the preceding ; fore part short, rounded, hinder part scarcely 
angulated; ventral margin strongly arcuated. Outside “dark green and very much radiated”; inside 
bluish-white and very iridescent. 
Long. 35; alt. vert. 24, ale 25, diam. 14 millim. Vertices in ? long. 
Hab, Cuntrat Nicaragua: Lake of Nicaragua (Bridges &-8). 
