﻿150 I.AMl'Sll.lS 



Unio bealei Ui\, Pr. Ac. N. Sci. Phila., YI. 1862, p. 169; Jl. 



Ac. N. Sci. Phila., V, 1862, p. 204, pi. xxx, fig. 273; Obs., 



IX, 1863, P- 26, pi. xxx, fig. 273. 

 Mar gar on (Unio) bealei Lea, Syn., 1870, p. 49. 



The species was described from a young, delicate male shell. 

 Afterwards Lea described a young female as Unio bairdianus 

 and still later Unio bealei from a larger, somewhat compressed 

 male shell. 



Var. coiiipressa Simpson. 



Shell subcompressed to compressed, rather thin, high and 

 short, of an almost regular elliptical outline. 



Type locality, southwestern Texas. 

 L.ainpsilis te.vasensis var. conipressus Simpson, Syn., 1900, p. 



564. 



All the specimens I have seen of the variety seem to be a 

 little diseased, yet the form diflfers so widely from the type 

 that I cannot believe it to be the result of pathologic influences. 



Lampsilis mearnsi Simpson. 



Shell short or long elliptical, considerably inflated, quite 

 solid, with a well-developed, narrowly rounded post^basal ridge, 

 with full elevated beaks, whose sculpture consists of a few 

 singly looped, wavy ridges well drawn up behind ; surface with 

 irregular growth lines, greenish-yellow often with one or more 

 dark green bands, usually the lower part of the posterior end 

 of the shell is dark green, the patch ending quite abruptly in 

 front. Sometimes there is one very broad green ray just be- 

 hind the center and occasionally this is split into finer rays ; epi- 

 dermis rather silky ; left valve with two compressed, slightly 

 recurved pseudocardinals, and two long laterals, which extend 

 to the pseudocardinals ; rig'ht valve with one pseudocardinal, 

 a faint one above it. and one lateral ; beak cavities shallow ; 

 muscle scars well impressed ; nacre white, ilesh-color or pale 

 salmon, rich and silvery iridescent, thiimer behind. The male 

 shell is much larger and longer than that of the female ; it has 

 a slight, somewhat angular projection at the post-base, the pos- 

 terior point is sharp and elevated midway up from the base, 



