200 NEW UNIONIDiE OF THE 



Hah. — Stewart's Mill Dam. Union County, North Carolina, Dr. Genth. 



My cabinet. 

 Diam. 1*1 j Length 15, Breadth 3 inches. 



Shell smooth, widely elliptical, inflated, inequilateral, obliquely angular behind, 

 rounded before ; substance of the shell rather thick, thicker before ; beaks rather 

 prominent ; ligament rather large and dark brown ; epidermis dark brown, lighter 

 towards the margin, with many obscure rays, shining, with distant, well marked 

 lines of growth ; umbonial slope inflated and rounded ; posterior slope flattish, with 

 two obscure, impressed lines on each valve from the beaks to the margin on both 

 valves ; cardinal teeth rather large, compressed and crenulate ; lateral teeth long, 

 lamellar and nearly straight ; anterior cicatrices distinct, large and well impressed ; 

 posterior cicatrices confluent, large and very slightly impressed ; dorsal cicatrices 

 placed across the centre of the cavity of the beaks; cavity of the shell deep 

 and wide ; cavity of the beaks rather deep and rounded ; nacre salmon color and 

 very iridescent. 



Remarles. — A single specimen only was obtained by Dr. Genth. It belongs to the 

 group of which Mashvillensis (nobis) may be considered the type. This is probably a 



i Ncis 

 :ry c 



male, and it very closely resembles the male of Nashvillensis. It also reminds one 

 of concestator and Whiteianus, (nobis,) as well also Mississippiensis, Con. It is wider 

 than the two first, but not so wide as the last. The rays are numerous and close 

 over the posterior half, but are dark and somewhat obscure in this specimen. In 

 others they may be better developed, particularly in younger specimens. In older 

 individuals they may be more obscure. The nacre of this specimen is of a fine rich 

 salmon. In other individuals the nacre may be found to be purple and white. 

 The beaks are too much eroded to make out the undulations of the tips. In this 

 specimen there is a small thin division of the cardinal tooth in the left and a 

 well defined double tooth in the right valve. Other specimens may not always 

 present this triple cardinal tooth. 



Unio squameus. PI. 28, fig. 269. 



Testa lasvi, suboblonga. valde conipressa, ineequilaterali, postice obtuse biangulata, antice rotundata ; 

 valvulis subcrassis, antice paulisper crassioribus ; natibus prominulis ; epidermide vel rufo-fusea 

 vel tenebroso-fusca, striata, inferne squamosa, obsolete radiata ; dentibus cardinalibus subgrandi- 

 bus, eompressis, striatis, in utroque valvulo subduplicibus ; lateralibus praslongis, larnellatis, 

 obliquis subrectisque ; niargarita alba et valde iridescente. 



Shell smooth, suboblong, very much compressed, equilateral, obtusely biangular 

 behind, rounded before ; valves rather thick, slightly thicker before ; beaks a little 

 prominent ; epidermis reddish brown or dark brown, striate, squamose below, ob- 

 scurely radiate ; cardinal teeth rather large, compressed, striate, somewhat double in 



