﻿LAMPSTUS 143. 



intermediates, which I could not satisfactorily place. The 

 texture of typical forms is different from that of amygdalum, 

 being decidedly waxy, and the nacre is rather more silvery. 



Lampsii.is vili.osa (B. H. Wright). 



Shell long obovate, subsolid, somewhat inflated, its greatest 

 diameter just forward of the center, rounded before and be- 

 hind ; posterior ridge almost wanting ; beaks low but moder- 

 ately wide, their sculpture not seen ; epidermis dark olive-green 

 to blackish, somewhat shining in the umbonal region, cloth-like 

 around the edges of the shell, rayless or very feebly rayed : left 

 valve with two ragged pseudocardinals, the anterior the 

 higher, sometimes partly connected on their upper edges and 

 having a faint pit between them, with two long, slender laterals ; 

 right valve v/ith one pseudocardinal and a vestige of one 

 above it, with one lateral ; beak cavities shallow ; muscle scars 

 scarcely impressed ; nacre bluish-white to lurid, somewhat iri- 

 descent and scarcely thinner behind. Female shell with a 

 slight, wide, rounded inflation at the post-base. 



Length 42, height: 23, diam. 17 mm. 



Suwanee and Escambia Rivers, Florida. 



Type locality, Suwanee River, Suwanee County, Fla. 

 Unio villosiis B. H. Wright, Naut.. XII, 1898, p. 32. 

 Lampsilis villosns Simpson, Pr. Ac. N. Sci. Phila.. 1900, p. 



77, pi. I, fig. I ; Syn., 1900, p. 562. 



A species combining the characters of L. amygdalum and 

 minor to some extent. The pseudocardinals have some resem- 

 blance to those of the latter. It is more elongated than either 

 species. 



Lampsii.is trossulus (Lea). 



Shell elliptical, suibinflated, rather solid, with full, slightly 

 elevated, anterior beaks, which are sculptured with distinctly 

 doubly-looped ridges, the hinder loop angular below : with a 

 moderately developed posterior ridge ; surface with low, con- 

 centric growth lines, smooth and shining, greenish-yellow with 

 faint rays, being quite green behind and wrinkled on the pos- 



