﻿146 I..\M1'SII.!S 



hind, thicker in front, lioth male and female shells are slightly 

 obovate and ronnded behind, the female has a considerablv 

 ])roduced rounded, marsupial swelling near the iX)sterior end. 



Length 30, height 17, diam. 13 mm. 



Florida and southwestern Georgia. 



Type locality, Lake Monroe and Lake George, Fla. 

 Unio minor Liva, Desc. 12 sp. Uniones, 1843; 1'r. Am. Phil. 



Soc., IX, 1846, p. 276, pi. XXXIX, fig. 3 ; Obs., IV, 1848, p. 



34, pi. XXXIX, fig. 3. — Simpson, Pr. U. S. Nat. Mus., XV, 



1892, p. 425, pi. LXVII, fig. 2. 

 Mari:^aron (Unio) minor Lea, Syn., 1852, p. 31, 1870, p. 49. 

 Lampsilis minor Simpson, Syn., 1900, p. 562. 

 Unio stearnsii B. H. Wright, Check List, 1888. 



The pseudocardinals of this species are so ])eculiar that it 

 would almost seem that it should grou]) by itself. The general 

 form, epidermis and nacre would seem to rather closely ally 

 it to varieties of L. amygdalum. 



Lampsims papyracea (Gould). 



Shell thin, obovate, subcompressed, with a low, posterior 

 ridge, beaks rather low, placed well forward, sculptured with 

 fine, doubly-looped ridges ; surface with numerous irregular 

 growth lines, the rest periods well marked, olive-green to rust- 

 brown, the younger shells with numerous indistinct rays, the 

 old shells often rayless ; epidermis sometimes a little silky or 

 cloth-like ; left valve with a long, low, irregular, compressed 

 pseudocardinal. the front end of it higher, and showing indi- 

 cations of being divided intO' two or three parts, with two well- 

 developed laterals; right valve with a rather high, compressed 

 pseudocardinal and a vestigial tooth above it, and one lateral ; 

 beak cavities shallow ; muscle scars faint, the posterior ones 

 scarcely discernible ; nacre bluish-white, iridescent through- 

 out, but especially so behind. Male shell full just behind the 

 center of the base, ending behind in a blunt, often feebly bian- 

 gulate point midway uj) from the base ; female shell nearly 

 evenly rounded behind and having a small, rounded marsupial 

 sw^clling placed well back. 



