OF CONCHOLOGY. 155 



DESCRIPTIONS OP NEW SPECIES OF NORTH 

 AMERICAN UNIONID^. 



BY JOHN G. ANTHONY. 



UXIO STRIATISSIMUS, Aiitliony. — t. 12, f. 1, 



Description. — Shell roughly striate, rhombic, depressed, 

 rather thick ; epidermis olivaceous, with green rays, more dis- 

 tinct at, and for a short distance below each mark of growth, 

 which lines become obsolete, or nearly so, about midway be- 

 tween two of the lines of increase; old specimens have these 

 rays so indistinct as to be scarcely perceptible, and the whole 

 shell presents a uniform, greyish -olive color ; beaks scarcely 

 elevated, wrinkled at tip ; marks of growth distant and very 

 distinct ; cardinal teeth large, broad, striate, deeply cleft in 

 the left valve; lateral teeth long, curved, and with a long, 

 smooth plate between them and the cardinal teeth ; anterior 

 cicatrices distinct and deep ; posterior cicatrices well im- 

 pressed, but confluent ; nacre white. 



Habitat. — Tennessee. 



My Cabinet. Cabinet of George "W. Tryon, Jr. 



Ohservations. — This species is remarkable for its unusually 

 rough exterior, being more rudely striate than any known 

 American species. This character, combined with its dull 

 greyish-olive color, its flattened form and rhombic outline, 

 will readily distinguish it from all others. Some forty or 

 fifty specimens have been observed, of all ages, and it is 

 probably not uncommon where found. It is somewhat 

 remarkable that so striking a species, oecurring in a region 

 often explored, should have so long been overlooked, which 

 may, however, be owing to its being very local in habitat. 

 May be compared with U. scamnatus, Mor., which it resembles 

 somewhat in striation, but its form is less elongate, it is pro- 

 portionally broader, more depressed, and its strias are not so 

 erect and prominent as in that species. From IT. straminevs, 

 Con., it differs in being less inflated, less elliptical, and its 

 marks of growth are more crowded and rougher than in 

 stramineus, while the color is very different. 



