DESCRIPTION OF FIFTY-TWO SPECIES OF TTNIONID^E. 9 



It is also near to Miirrai/ensis (nobis) and to mundus (nobis). One of the young 

 specimens has two or three undulations at the tips of the beaks. I have great 

 pleasure in naming this species after Miss Annie E. Law, of Concord, East Ten- 

 nessee. She has been a most energetic and successful collector of the mollusks 

 in the streams of that part of the State where she resides, and which have never 

 been so well examined as by herself. 



Unio obuncus. pi. 2, fig. 5. 



Testa Isevi, triangulari, subinflata, inEequilaterali, antice rotunda, postice obtuse angulata ; valvulis 



crassis, antice crassioribus ; natibus prominentibus; epidermide dilute oliva, perradiata; dentibus 



cardinalibus parvis eorrugatisqne; lateralibus crassis, lamellatiscorrugatisque; margarit^ argentea 



et iridescente. 



Shell smooth, triangular, somewhat inflated, inequilateral, round before, obtusely 

 angular behind; valves thick, thicker before; beaks prominent; epidermis pale 

 olive, much radiated ; cardinal teeth small and corrugate ; lateral teeth thick, 

 lamellar and corrugate ; nacre silver white and iridescent. 

 Proc. Acad Nat. Sci., 1811, p. 192. 



^a6.— Tuscumbia, Ala., L. B. Thornton; Holston River, E. Tenn., Miss Law. 



My cabinet and cabinet of Dr. Lewis. 

 Diam. -8, Length 1'3, Breadth 1-5 inch. 



Shell smooth, triangular, somewhat inflated, inequilateral, round before and 

 obtusely angular behind; substance of the shell thick, thicker before; beaks promi- 

 nent, somewhat pointed; ligament short, rather thick and brown; epidermis pale 

 olive, rayed all over, somewhat polished, with distant marks of growth ; umbonial 

 slope raised into an obtuse angle and curved slightly inward towards the basal 

 margin ; posterior slope subcordate, with thin rays from the beaks to margin ; car- 

 dinal teeth small, thick, and much corrugated ; lateral teeth thick, lamellar and 

 corrugated; anterior cicatrices distinct, small and deeply impressed; posterior 

 cicatrices distinct, rather small and well impressed ; dorsal cicatrices placed along 

 the base of the cardinal tooth ; cavity of the shell shallow and wide ; cavity of the 

 beaks deep and angular ; nacre silvery white and iridescent. 



B.e7narks.—T\).exe are seven specimens before me; they were all sent by Miss 

 Law to Dr. Lewis. It is a pretty little species, closely allied to Edgarianus (nobis), 

 and has some resemblance to young Mooresimms (nobis). Like Edgarianus it has 

 fine green rays, but it has not the great inflation of the anterior half of the disk, 

 like that species, nor has it the high polish, nor the deep green rays on the anterior 

 portion. It is also closely allied to Tuscumbiensis (nobis), but may be distinguished 



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