﻿LAMPSILIS 153 



swelling, just behind the middle of the base, and the posterior 

 end blunt, rounded, and a little elevated. 



Length (male) 70, height 40, diam. 25 mm. 



Length (female) 57, height 33, diam. 22 mm. 



Alexandria, I,ouisiana : eastern Texas. 



Type locality. Mississippi River, thirty miles above New 

 Orleans, La. 

 Unio haleianus Lka, Pr. Am. F*hil. Soc, II, 1842, p. 224; Tr. 



Am. Phil. Soc, VIII, 1842, p. 247, pi. xxvii, fig. 63; Obs., 



Ill, 1842, p. 85, pi. XXVII, fig. 63. — Chenu, 111. Conch., 1858, 



pi. XXVI, figs. 6, 6a, 6b. — ? Reeve, Conch. Icon., XVI, 1865, 



pi. XXIV, fig. 116. 

 Margaron (Unio) haleianus Lea, Syn., 1852, p. 31 ; 1870, p. 49. 

 Lavipsilis haleianus SiMrsoN, Syn., 1900, p. 564. 



This species is close to L. texasensis, but is larger and thin- 

 ner, and the epidermis is usually lighter colored. The female 

 shell is more rounded behind than it is in texasensis. Specimens 

 have been found in Old River. Victoria County, Texas, which 

 agree very well with haleiana in size, form and solidity, but 

 which have a darker epidermis and a pale, dirty salmon nacre. 

 I cannot be certain which species they should be referred .to. 

 The /.. haleiana sometimes has doubly-looped beak sculpture. 



Lampsius gi.ans (Lea). 



Shell short elliptical, rather solid, inflated, with a low, round- 

 ed posterior ridge, and a decided lunule, with full, high beaks, 

 having irregular, subnodulous ridges, which curve up somewhat 

 behind, and are nodulous at the posterior ridge, returning by 

 converging lines to the embryonic shell ; surface wnth irregular,, 

 growth lines, rayless, covered with a dark brownish, thick epi- 

 dermis ; left valve with two irregular, ragged pseudocardinals, 

 which are often imited by a ridge at their upper sides, and two 

 laterals ; right valve with one pseudocardinal and sometimes 

 a vestige of another above it, and two laterals, or with one and 

 a faint second one below it ; beak cavities shallow ; muscle scars 

 well impressed ; nacre generally purple and lighter on the bor- 

 der, though sometimes creamy white, suddenly becoming thin- 



