40 



terminal ; sloped and nerved posteriorly ; epider- 

 mis wrinkled, brownish with dark spots ; nacre 

 flesh coloured. Length J- diam. T \ axis T \ 

 of the breadth. 



A small and rare species ; scarcely more than 

 an inch in breadth ; found in the Kentucky ; 

 shell thin posteriorly ; nerves obliquely curved on 

 the dilated posterior edge ; one or two hunches 

 on the oblique elevation ; lamellar tooth short, and 

 broad ; cardinal tooth striated ; no fossule. 



SPECIES XXXI. Obliquaria reflexa (Unio 

 reflexa.) 



Shell thick, convex, hunched, almost rounded, 

 truncated posteriorly ; inferior edge reflected, 

 having a posterior sinus; epidermis reddish, al- 

 most smooth, rugose posteriorly ; nacre white, 

 iridescent. Length diam. f axis ^ of the 

 breadth. Breadth one and an half inches. 



Attenuated posteriorly ; two hunches on the 

 medial elevation ; its end reflected ; wrinkles se- 

 parated, flexuous in the form of sutures ; lamellar 

 tooth prolonged, carinated, very slightly curved ; 

 cardinal tcoth very much striated ; fossule visible. 

 Found in the Kentucky and at Letart's rapids : 

 may not this species belong to the sub-genus 

 Rotundaria ? 



