ANODONTA. 525 
B. Sinulus deep, triangular, pointed. 
[Neotropical species. ] 
IV. Scorranopon, n.—Oval, summits somewhat unequal. Only known from the Lake of Nicaragua. 
—A. inequivalvis, lenticularis, granadensis. 
V. Evryanopon, Fischer & Crosse (1893).—Elongated, dorsal margin not ascending posteriorly : 
A. bambusearum, Morelet, and probably also A. cylindracea, Lea, from EH. and S.E. 
Mexico; A. amazonensis, Lea, from the Upper Amazons. 
Anodonta solidula, Hupé, and some nearly allied species are not far from this group, and 
lead to Lamproscapha, Swains. (1840), type A. ensiformis, Spix. 
VI. Guasaris, Gray, P. Z. S. 1847, p. 206; Conrad (1857).—Oblong, dorsal margin forming a 
straight line before and behind the summits, subangulated at its fore and hinder ends. 
Inside very iridescent: 4. nicarague and jewetti, from Central America; A. exotica, Lam., 
A. anserina, Spix, A. forbesiana, Lea, &c., from South America. 
VII. Psrvporera, Fischer & Crosse (1893).—Near the preceding, but distinct by the remarkable 
gaping of the underside of the fore extremity : A. ciconia, from N.W. Mexico. 
Differs from the South-American Leila, Gray, in the want of a pallial sinus. 
VII. Pacnyanopon, n.: “ Anodonte latomarginatz,’’ v. Martens, in Malak. Blatt. 1868, p. 211; 
Die dickschaligen siidamerikanischen Anodonten, Clessin, in Martini & Chemnitz, Syst. 
Conch.-Cab. ed. 2, Anodonta, p. 77.—Rounded, solid; the dull lustreless zone inside the 
ventral and posterior margins very broad: A. latomarginata, Lea, and other species from 
South America; A. luteola, from the Isthmus of Darien. 
IX. Sryeanopon, n.—Shell more or less reniform, inside more or less dark and dull, with a broad 
lustreless marginal zone as in Pachyanodon: type A. tenebricosa, Lea, from South America. 
Not yet known from Central America. 
ANODONTA, sensu strictiore. 
1. Anodonta coarctata. (Tab. XL. figg. 1-7.) 
Anodonta coarctata, Anton, Verz. d. Conch. p. 16. no. 583 (1839) '; Kiister, in Martini & Chemnitz, 
Syst. Conch.-Cab. ed. 2, Anodonta, p. 34, t. 8. fig. 2°; Fisch. & Crosse, Miss. Scient. Mex., 
Moll. ii. p. 519° (nee A. coarctata, Potiez et Michaud, Galerie Moll. 1844). 
Anodonta chapalensis, Crosse & Fisch. Journ. de Conch. xl. p. 295 (1892) *; Miss. Scient. Mex., 
Moll. ii. p. 518, t. 64. figg. 8-11”. 
Oval, shortly rounded before, elevated and produced behind, moderately convex, olivaceous-greenish, with 
blackish lines of growth; ventral margin moderately arcuated, ascending more distinctly before than 
behind; dorsal margin ascending behind the summits to as far as the notch (sinulus) of the ligament and 
there forming an obtuse angle with the descending posterior margin, which becomes almost vertically 
truncated in its lower half. Inside dull bluish, in the centre pale greyish-violet or dull orange, not very 
iridescent ; the dull marginal zone rather narrow. Summits much worn. 
a. Long. 68; alt. vert. 37, ale 39, diam. 234 millim. Vertices in } long. 
6. ” 624 ; ” 354, Skee 9 22 2 2 ty ” 
Co ” 62 ; ' ” 334, i Ote yp 214 ra ” t+ oo” 
d. yo OP ” 34, 5, 38,» 23 » 2 4 ry 
Ce 9 51; 99 31, 5; 34, ay 15 ey) ry 7 oo 
7. » OLS 29 283, 49 Oy 9 163 9 ” z ” 
