OQUADRULA g2I 
Castalia nodulosa H. and A. ApAmMs, Gen. Rec. Moll., II, 1857, 
p. 509. 
Umio grandidens Lema, Pr. Ac. N. Sci. Phila., V, 1862, p. 168; 
piece. No Seis Phila. V, 1862; p. 205,-pl. xxx, fig. 274; Obs:, 
DX 1863* pn 27, phi-xx kis. 277: 
Margaron (Unio) grandidens Lia, Syn., 1870, p. 34. 
I have before me two opposite, matched valves of this spe- 
cies, the right valve being Lea’s figured type of Unio grandi- 
dens, the left one accompanying it and sent as from Hot 
Springs, Arkansas, by Dr. Byrd Powell to the Smithsonian 
Institution. ‘The valves agree exactly with Wood's figures 
and brief description of M/ya nodulosa. his shell certainly 
never caine from Arkansas and it has the characters of Heude’s 
Unio polystictus in such a degree that [ suspect that the two 
run together. It 1s a very heavy shell, much more nodulous 
and strongly sculptured than Q. tortwosa, tientsinensis, zonata 
or fibrosa. 
Wood gives four figures of his Mya nodulosa, the first and 
second being a solid, nodulous, Chinese species; the third and 
fourth seem to be Unio pictorum. Lamarck used the name 
nodulosa for a Unio (An. sans Vert. VI, 1819, p. 78), and 
refers to the Encyclopedia Methodique, pl. 248, fig. 19, 1797, 
and this figure is no doubt that of Unio pictorum. Wood 
seems to have confounded the two. 
QUADRULA LIEDTKEI Rolle. 
“This magnificent, heavy, massive, nodulously sculptured 
species, which is not inferior to the finest North American 
species, stands nearest to the Chinese Unio nodulosus Wood, 
(grandidens Lea), but differs by the incurving of the anterior 
margin immediately under the beaks, where there is a distinct 
lunule, which is wanting in the Chinese species. “The cardinal 
tooth of the right valve is also less deeply paralleled grooved. 
I give four figures of the shell and can well dispense with a 
precise description. 
Length 138, height 90, diam. 90 mm.” (Rolle). 
Type locality, Riviere Claire, Tonkin. 
