508 MOLLUSCA. 
species. It differs, however, from all the Cuban specimens of U. scamnatus, Morelet, 
in the Berlin Museum, in the more quadrate form, the height equalling the length (in 
the Cuban examples which most nearly approach it the height is only two-thirds of the 
length), the more abruptly descending hinder dorsal margin, the rather less compressed 
form of the whole shell, and the greater strength of the cardinal teeth. ‘The umbones, 
when well preserved, are strongly furrowed concentrically. The relative proportion of 
the length to the height of the shell varies in specimens from the same locality between 
about 3:2 to 2:1 (specimen @). 
At first sight this specimen resembles U. litoralis, Cuv., from Western Europe ; it 
differs, however, on closer inspection, in having the concentric ridges closer together, 
those in the umbonal region very distinct and regular, while in U. ltoralis they are 
more depressed and distant, and in the umbonal region undulated. 
33. Unio championi, sp.n. (Tab. XX XVIII. figg. 9, 9 a.) 
Testa oblongo-elliptica, concentrice dense et inzqualiter striata, fusca, in regione umbonali pallidior, obscure 
viridi-radiata, et pone umbones lirulis nonnullis radiantibus brevibus, interdum duabus, sulcum in- 
cludentibus, magis elongatis, sculpta, antice rotundata, verticibus parum prominulis, margine dorsali 
posteriore primum leviter declivi, dein magis descendente, extremitate postica rotundato-truncata, margine 
ventrali leviter convexo, antice et postice subequaliter ascendente; dentes cardinales subcompressi, 
margini paralleli, leves ; facies interna cerulescens. 
Long. 30 ; alt. vert. 17, ale 16, diam. 63 millim. Vertices in 2 long. 
Hab. W. GuatemaLa: Paso Antonio, in the Pacific coast-region (Champion). 
Differs from U. hyalmarsoni, Dunk., in having the fore part shorter and more broadly 
rounded, and the concentric strie more feeble and not so broad, as well as in the 
arcuated before and more abruptly ascending behind, straight or very slightly convex at the middle; 
height of the shell more than half its length ; summits in 3-2 of the length; inside bluish-white. 
a. Long. 55; alt. vert. 30, ale ?, diam. 17 millim. (Morelet). 
b. » 08; ” 32, 45 34, 4, 18 ” 
C. » 83; am 37, ,, 387, ,, 222 ,, > (specimens in Berlin Museum). 
d. ,, 64; » 983, 5 30, , 18 ,, j 
Hab. Cusa: Cacajajicara (Morelet), Rio Taco (Gundlach). 
Unio proclinatus, sp. n. 
Unio scamnatus (Morelet), Dunker, Malak. Blatt. v. p. 229 (1858). 
Unio gundlacht (Dunker), Sowerby, in Reeve’s Conch. Icon. xvi., Unio, t. 46. fig. 248. 
Elongate, sulcated, compressed ; fore part very short, abruptly rounded; hinder half lower, strongly com- 
pressed ; ventral margin conspicuously ascending before, subsinuated at the middle, scarcely ascending 
behind ; height of the shell equalling half its length or somewhat less ; summits in 2-7 of the length; 
cardinal teeth somewhat stronger ; inside orange or somewhat purplish. 
a. Long. 84; alt. vert. 40, alee 36, diam. 20 millim. 
b. ss 60; ” 30, ” 273, » 16 ” 
C. ” 58 ; ” 25, » 28, , 14 ” 
Hab. Cusa: Rio Taco and Gibara, in the eastern part of the island, and Pinar del Rio, farther west (Gundlach, 
am Mus. Berol.). 
