GG NEW UNIONIDiE OF THE UNITED STATES. 



Remarks.— Two specimens only were received— one probably full grown, from 

 which the figure is made, the other probably one-third grown. The former is no 

 doubt adult. It is nearly allied to EntabrooJdanua, (nobis), and somewhat in outline 

 to rubiginosus. It is sulcate like the former. The young specimen has an indistinct 

 ray down the middle of the disks, the adult one a few indistinct rays near the beak. 

 The tips of the beaks of these two specimens are too imperfect to observe their undu- 

 lations. 



I name this after Mr. Meredith, a young student of natural history, to whose indus- 

 try I owe this and many other shells from the same habitat. 



Unio pehradiatus. PL 6, fig. 215. 



Testa Ijcvi, subtriangulari, inflata, postice obtuse biangulata, subinsequilaterali ; valvulis crassiuseulis, pos- 

 tice crassioribus ; natibus subgrandibus, tumidis et incurvis ; epidermide nitida, lutea et tota virido- 

 radiata ; dentibus eardinalibus parviusculis, valde" crenulatis, in utroque valvulo duplicibus ; lateralibus 

 subbrevibus, lamellatis subcurvisque ; margarita alba et iridescente. 



Shell smooth, subtriangular, inflated, obtusely biangular behind, rather inequilate- 

 ral ; valves a little thick, thicker before ; beaks rather large, swollen and incurved ; 

 epidermis shining, yellow, with green rays over the whole disk ; cardinal teeth rather 

 small, very much crenulate, double in both valves ; lateral teeth rather short, lamellar 

 and curved ; nacre white and iridescent. 

 Proo. Acad. Nat. Sci. 1858, p. 40. 



Bob. — Florence, Alabama. Rev. George White. 

 My cabinet and cabinet of Mr. White. 

 Diam. 1-2, Length 1-5, Breadth 2*3 inches. 



Shell smooth, subtriangular, inflated, obtusely biangular behind, rather inequi- 

 lateral ; substance of the shell a little thick, thicker before ; beaks rather large, 

 swollen, incurved ; ligament rather long, thick and dark brown ; epidermis shining, 

 yellow, with green rays over the whole disk ; umbonial slope raised, obtusely angular ; 

 posterior slope wide, subcordate, with a furrow in each valve from the beaks to the 

 margin; cardinal teeth rather small, very much crenulate, double in both valves; 

 lateral teeth rather short, lamellar and curved ; anterior cicatrices confluent, rather 

 large and well impressed; posterior cicatrices distinct, large and moderately im- 

 pressed ; dorsal cicatrices placed over the centre of the cavity of the beaks and across 

 the base of the cardinal tooth; cavity of the shell deep and large; cavity of the beaks 

 deep and obtusely angular ; nacre white and iridescent. 



Remarks. — I have seen but a single specimen of this species. It is very imperfect 

 about the beaks, and therefore the form of the undulations is not ascertained. It be- 

 longs to the group of which multiradiatus (nobis) may be considered the type, but it 

 differs in being more inflated and in not having an elliptical outline. 



