﻿LAMPSir.IS 



103 



Unio intercedens Lea, Pr. Ac. N. Sci. Phila., IX, 1857, ?• 3^ ; 



Jl. Ac. N. Sci. Phila., IV, 1858, p. 77, pi. xv, fig. 57; Obs.i 



YI, 1858, p. 77, pi. XV, fig. 57. 

 Margaron (Unio) intercedens Lea, Syn., 1870, p. 45. 

 Unio fallax Lea, Pr. Ac. N. Sci. Phila., IX, 1857, P- 32 ; Jl. Ac. 



N. Sci. Phila., IV, 1858, p. 79, pi. XV, fig. 59; Obs., VI, 1858, 



p. 79, pi. XV, fig. 59.— KusTER, Conch. Cab. Unio, 186 1, p. 



206, pi. 1.XV111, fig. 7.— SowERBY, Conch. Icon., XVI, 1868, 



pi. Lxxx, fig. 418. 

 Margaron (Unio) fallax Lea, Syn., 1870, p. 45. 

 Unio contiguus Lea, Proc. Ac. N. Sci. Phila., VI, 1861, p. 392; 



Jl. Ac. N. Sci. Phila., V, 1862, p. 199, pi. xxviii, fig. 268; 



Obs., IX, 1863, P- 21, pi. XXVIII, fig. 268. 

 Margaron (Unio) contiguus Lea, Syn., 1870, p. 45. 

 Unio bi-ccelatm Reeve, Conch. Icon., XVI, 1865, pi. xxvi, fig. 



130. 

 Unio genuinus Lea, Pr. Ac. N. Sci. Phila., XX, 1868, p. 161 ; 



Jl. Ac. N. Sci. Phila., VL 1868, p. 305, pi. xlvi, fig. 117; Obs., 



XII, 1869, P- 64, pi. XLVI, fig. 117. 



Margaron (Unio) genuinus Lea, Syn., 1870, p. 45. 



Very close to L. Henosa, and there are specimens which I am 

 unable to satisfactorily determine. As a rule Henosa is a larger 

 shell, is darker colored and not quite so shining, and it is solider. 



IvAMPSius PROPRIA (Lea). 



Shell rather small, long elliptical or subrhomboid, subsolid 

 and subinflated, with rather low beaks, with a low, rounded 

 posterior ridge; surface generally smooth, pale, smoky yellow- 

 ish, sometimes with very faint rays behind ; pseudocardinals 

 subcompressed ; laterals short and lamellar ; muscle scars shal- 

 low ; nacre whitish, darker and often salmon or purplish in the 

 center of the valves, but slightly thicker in front. Male shell 

 subrhomboid, the somewhat rounded posterior point being near 

 the base of the shell ; female shell with but a moderate mar- 

 supial swelling, the posterior point a little more than midway 

 up from the base. 



