254. NEW UNIONIDiE, MELANID^, ETC., 



Unio Emesaensis. pi. 30, fig. 68. 



Testa loevi, subrotunda, inrequilaterali, ad umbones subtumida, antice rotundata, postice obtuse sub- 

 biangulata ; valvulis crassiusculis, antice aliquanto crassioribus ; natibus prominentibus, ad apices 

 valde corrugatis ; epidermide rufo-fusca et obsolete radiata ; dentibus cardinalibus subcrassis et 

 crenulatb ; lateralibus brevibus subrectisque ; margarita vel purpurea vel alba vel aurea et valde 

 iridescente. 



Shell smooth, subrotund, inequilateral, swollen at the beaks, I'ounded before and 

 obtusely biangular behind ; valves somewhat thick, a little thicker before ; beaks 

 prominent and very corrugate at the tips; epidermis reddish-brown and obscurely 

 rayed ; cardinal teeth rather thick and crenulate ; lateral teeth short and nearly 

 straight ; nacre purple, white or golden, and very iridescent. 

 Proc. Acad. Nat. Sci. 1864, p. 286. 



Hob. — Lake Horns, River Orontes, North Syria (ancient Emesa), C. M. Wheatley. 



My cabinet and cabinet of Mr. Wheatley. 

 Diam. "8, Length 1-2, Breadth 1'7 inch. 



Shell smooth, subrotund, inequilateral, swollen at the beaks, rounded before and 

 obtusely angular behind ; substance of the shell somewhat thick, a little thicker 

 before; beaks prominent and very corrugate at the tips; ligament «hort, rather 

 thick and light brown ; epidermis reddish-brown, obscurely rayed, with distant 

 marks of growth above and close below ; umbonial slope rounded ; posterior slope 

 elliptical, slightly raised, with two green rays from the tips to the posterior margin ; 

 cardinal teeth rather thick, crenulate, single in the right and double in the left 

 valve; lateral teeth short, rather thick and nearly straight; anterior cicatrices dis- 

 tinct and well impressed; posterior cicatrices distinct, rather large and well 

 impressed ; dorsal cicatrices placed nearly in the centre of the cavity of the beaks ; 

 cavity of the shell rather deep ; cavity of the beaks rather deep and angular ; nacre 

 white, purple or golden and very iridescent. 



Remarhs. — I have seven specimens of this species from Mr. Wheatley, collected for 

 him by the Rev. Mr. Beadle. Six of these are marked " Lake Homs, North Syria ;" 

 and one " Northern Egypt." There is no doubt of their being the same species, and I 

 cannot doubt but that all are from Lake Homs. The oldest specimen is much 

 eroded, with little epidermis remaining, and the nacre destroyed on the surface of the 

 cavity. The others are younger, and show corrugated wrinkles to the tips of the 

 beaks. This species approaches in outline and other characters to that of semiru- 

 gatm, Lam., which I had, in my "Synopsis," considered a variety oilitoralw, Lam., 

 but which I am now satisfied is distinct, although very closely aUied in many of its 

 characters. The semirugatas differs from our shell in being more rounded in outline, 

 and the undulations of the beaks differ. It is also redder in the epidermis. In the 



