FAMILY UNIONIDjE — UNIO. 193 



Unio OCHRACEUS. 



PLATE XIX. FIGS. 237, 838. 



(STATE COLLECTION.) 



Unio ochraceus. Say, Nich. Encyl. Vol. 4, pi. 2, fig. 8. 



Symphonota ochracea, and Margarita id. Lea, Am. Phil. Tr. Vol. 3, p. 69; Vol. 6, p. 126, pi. 15, fig. 44. 



U. ochraceus. Conkad, Monog. Unionida:, pi. 17, fig. 2. Gould, Inv. Mass. p. 112, fig. 74. 



Description. Shell thin, translucent, subovate, ventricose : valves smooth. Hinge-margin 

 nearly straight, angulated at each end. Beaks elevated and approximated, directed forwards, 

 with a few concentric undulations. A rib, strongly impressed within, passes obliquely from 

 the beaks to the posterior margin, enclosing a depressed area with the margins carinated ; 

 this rib gives a subangulated appearance to the posterior margin : the other extremity rounded, 

 gaping. Cardinal teeth very oblique and much compressed, striated, and nearly parallel with 

 the hinge-margin ; lateral teeth short. 



Color. Epidermis varying from pale reddish to yellow olive and green, with colored radia- 

 tions and dusky concentric bands ; within bluish tinged with red, occasionally uniform rose-red, 

 and often of a beautiful scarlet or salmon-color. 



Vertical axis, 1 • - 2' ; transverse ditto, 1 ' 8   2' 8. 



Fig. 237 is from the Mohawk river. The variety fig. 238, from Second river near Belleville, 

 is introduced for its brilliant interior, and is more solid than any specimens which have come 

 under my notice. 



Unio cariosus. 



PLATE XXI. FIGS. 243, and 244 (Variety). 



Unio cariosus. Say, Nich. Ency. Vol. 4, pi. 3, fig. 2. Barnes, Am. Jour. Vol. 6, p. 271/ 



U. cariosa. Lamarck, An. sans vert. Vol. 3, p. 671, Ed. Unix. 



U. ovata. Val. Obs. de Zool. Vol. 2, p. 226, pi. 50, fig. 1. 



Margarita ( Unio) cariosa. Lea, Trans. Am. Phil. Soc. Vol. 6, p. 126, pi. 15, fig. 45. 



Unio cariosa. Conrad, Unionidae, p. 40, pi. 19 {crassus, Say). Conrad, Fr. Wat. Sh. p. 63. 



U. id. Gould, Inrertebrata of Massachusetts, p. Ill, fig. 72. 



Description. Shell ovate, inflated, moderately thin. Beaks somewhat prominent, much 

 eroded, with a prominent ridge passing from the beaks to the posterior margin. Teeth 

 oblique : cardinal teeth broad, oblique and compressed. Cavity of the beaks moderate. Sur- 

 face occasionally verrucose. 



Color. Epidermis olive brown or greenish, commonly with a few distant deep green nar- 

 row radiations, most conspicuous on the posterior portion ; the decorticated beaks wax-yellow 

 or opake white : within, bluish white, rose-red, and even salmon-color. 



Vertical axis, 2  - 2 * 5 ; transverse ditto, 3 * 5 - 4 • 0. 



This fine shell is found of extraordinary size and beauty in the River Passaic, near Belle- 

 ville. Those from the Hudson are usually smaller and less solid than the Jersey specimens. 



Fauna — Part 6. 25 



