﻿140 I.AM PS I LIS 



LaMI'SII.IS AMYGDAI.l'M (Lca). 



Shell elliptical or obovate, somcwliat inllatcd, with full, rath- 

 er high beaks, which are sculptured with fine, doubly-looped 

 bars; color varying' from dirty greenish-white to almost black, 

 with numerous rather faint rays or rayless ; epidermis smooth 

 and shining to rather rough, dull and cloth-like ; left valve with 

 two elongated, compressed pseudocardinals and two delicate 

 laterals ; right valve with one pseudocardinal and a single lat- 

 eral ; beak cavities not deep ; muscle scars shallow ; nacre bluish- 

 white, creamy or bnff-colored. soft and brilliant, richly irides- 

 cent behind. The shells are very variable in form and degree 

 of solidity ; the males are generally elliptical with a low, round- 

 ed posterior ridge, with a slight dorsal wing and a more or less 

 blunt posterior point about midway up from the base. The fe- 

 male shell is usually narrowed and rounded m front, and is al- 

 most always darker and rougher than that of the male. 



Length 47, height 29, diam. 18 mm. 



Florida. 



Type locality, I.ake George, Fla. 

 Unio amygdalum Lea. Desc. of twelve sp. Uniones, Aug. 19, 



1843; Tr. Am. Phil. Soc, IX, 1846, p. 275, pi. xxxix, fig. i ; 



Obs., IV, 1848, p. 33, pi. XXXIX, fig. I. — Simpson, Pr. U. S. 



Nat. Mus., XV, 1892, p. 426, pi. Lxvii, fig. 3. 

 Margaron (Unio) amygdalum Lea, Syn., 1852, p. 39; 1870, 



p. 62. 

 Lampsilis amygdahim Simpson, Syn., 1900, p. 561. 

 Unio Icpidus Goui.d. Pr. Bost. Soc. N. Hist., VI, 1856, p. 15: 



Otia Conch., 1862, p. 222. — Simpson, Pr. U. S. Nat. Mus., 



XV, 1892, p. 426, pi. I, XVII I, fig. I ; pi. Lxix, fig. 3. 

 Margaron (Unio) lepidus Lea, Syn., 1870, p. 39. 



This is an excessively puzzling form. Generally, but not 

 always, the female shell is darker and rougher than that of the 

 male. The form usually known as lepidus, is ordinarily larger 

 and a little more elongated than typical amygdalum and it is 

 larger and solidcr. though I have specimens before mc that are 



