S4 rafinesque's 



a zigzag form in the middle, inside silvery white, teeth subequal, 



much curved. Length 2-3, diameter 2-5, axis 5-12 of the breadth. 



Also from the river Jellinghy. Small, hardly one inch. This 



and the last agree in many points, and might form a peculiar sub- 



[7] 

 genus Hemisolasma, having shell ovate, axis submedial, lamellar 



teeth subequal. 



118 Sp. JJnio fulgens, \_Lampsilis fulgens.'] 



Shell thick, elliptical, swelled, attenuated behind, outside nearly 

 smooth, laminated, ferruginous brown ; inside of a beautiful 

 metallic incarnate and iridescent. Length 1-2, diameter 1-3, axis 

 1-5 of the breadth. 



From the river Ganges, two or three inches, beautiful shell, a true 

 Lampsilis, with a long flexuose lamellar tooth subcrenulate ; cardinal 

 tooth compressed crenulate. Anterior fossule, very conspicuous 

 below the anterior impression. 



119 Sp. Unio Ai-gyratus, [^Lampsilis argyratus.'} 



Shell thin, elliptical, swelled, attenuated behind, outside laminated 

 greenish, decoricated and silvery at the summit, inside bluish irides- 

 cent. Length 1-2, diameter 1-3, axis 1-16 of the breadth. 



Also from the river Ganges. Size one and a half inch. Very 

 near to the S. G. Leptodea, but teeth as in the last, cardinal small 

 crenulate, lamellar less flexuose, not crenulate. In both the teeth 

 are wide apart as in all the Lampsilis. 



120 Sp. Unio corrugata, of the authors from the river Baramputra, 

 it is an Obliquaria, very near to my U. Venus and U. Elliptica, S. 

 G. Aximedia. In Mr. Poulson's cabinet, I have not yet been able 

 to determine precisely whether it is well named, and not having the 

 specimen before me, I cannot describe it. 



10 N. G. LONCOSILLA. 



Shell transversal, unequilateral, somev^'hat gaping, only one mus- 

 cular impression anteriorly. No teeth as in Anodonta, but a hinge 

 with a marginal nerve, or fold anteriorly ; distinct from the margin, 

 and a little obliqual behind. Ligament small at the very summit. — 

 Animal unknown. 



A distinct genus of the tribe Anodonta, which had been mistaken 

 for a fluviatile Solen by Dr. Burroughs the discoverer of it ; but all 

 the Salens are marine shells. The name means little knife ; it is 

 different from all my S. G. of Anodonta. 



