272 SIX NEW SPECIES 



d the great posterior muscle. 



e the inferior right branchiae. 



/ the right oviduct. 



g the foot. 



h the superior left branchiae. 



i interior view of the oviduct. 



6. Unio Lacrymosus. Plate VI. fig. 8. 



Testa sub-quadra7igulari, incequilaterali, postice angulatd, transversa, 

 tuberculata ; dente laterali abrupte terminanie. 



Shell subquadrangular, inequilateral, angular behind, transverse, tu- 

 berculated; termination of lateral tooth abrupt. 



Hab. Ohio. T. G. Lea. 



My Cabinet. 

 Cabinet of T. G. Lea. 

 Cabinet of Prof. Vanuxem. 

 Diam. -9, Length 1-7, Breadth 1-8 inches. 



Shell rather depressed and rounded anteriorly — substance 

 of the shell thick — ^beaks slightl}^ elevated with the ligament 

 passing between them, recurved and almost touching, free 

 from decortication, and covered with beautiful delicate raised 

 points — when viewed on the back all the visible part is co- 

 vered with them — dorsal margin oblique; posterior dorsal 

 margin subangular, carinated ; posterior margin angular ; pos- 

 terior basal margin emarginate ; basal, anterior and anterior 

 dorsal and basal margins rounded — epidermis yellow-green 

 and very smooth, almost white at the point of the beaks, an- 

 teriorly slightly rayed — disks tuberculated, having a smooth 

 channel, margined by two rows of tubercles or raised points, 

 running from the point of the beaks, and diverging one to the 

 basal, the other to the posterior margin — tubercles, enlarging 

 towards the base, taking the form of flowing tears, and resem- 

 bling coagulated gum ; they are very minute at the point of the 

 beaks — undulated delicately along the posterior dorsal mar- 



