[55] 



SUPPLEMENT 



TO 



ISAAC LEA'S PAPEE 0:N" UIi^IOI^ID^. 



TJnio cirratus. pi. 19, fig. 53. 



Testa Isevl, oblonga, subcompressa, insequilaterali, postice obtuse biangulari, antice rotunda; valvulis 

 subcrassis, antice parum crassioribus; natibus prominulis; epidermide tenebroso-fusca, subcirrata, 

 eradiata; dentibus cardinalibus parviusculis, sulcatis, in utroque valvulo duplicibus ; iateralibus 

 sublongis, lamellatis subrectisque ; margarita vel alba vel salmonis colore tincta et valde iridescente. 



Shell smooth, oblong, somewhat compressed, inequilateral, obtusely biangular 

 behind, round before; valves somewhat thick, a little thicker before; beaks a little 

 prominent; epidermis dark brown, somewhat roughened, without rays; cardinal 

 teeth rather small, sulcate, double in both valves; lateral teeth rather long, lamellar 

 and nearly straight ; nacre white or salmon colored and very iridescent. 

 Proc. Acad. Nat. Sci., 1873, p. 422. 



Hab. — Abbeville District, South Carolina, Dr. J. P. Barratt. 



My cabinet and cabinet of C. M. Wheatley, 

 Diam. 1-1, Length 1-8, Breadth 3*2 inches. 



Shell smooth, oblong, somewhat compressed, inequilateral, obtusely biangular 

 behind, round before ; substance of the shell somewhat thick, a little thicker 

 before; beaks a little prominent; ligament rather large and dark brown; epidermis 

 dark brown, somewhat roughened, without rays and with rather close marks of 

 growth ; umbonial slope somewhat raised and rounded ; posterior slope subcarinate, 

 elliptical ; cardinal teeth rather small, sulcate and double in both valves ; lateral 

 teeth rather long, lamellar and nearly straight ; anterior cicatrices distinct, large 

 and well impressed; posterior cicatrices confluent, large and moderately impressed; 

 dorsal cicatrices placed above the centre of the cavity of the beaks ; cavity of the 

 shell rather deep and wide ; cavity of the beaks shallow and rounded ; nacre white 

 or salmon color and very iridescent. 



Remarks. — This species is closely allied to Abbemllensis (nobis), and is from the 

 same locality. For a long time I thought it a variety of that species, but by addi- 



