CONCHOLOGIOAI, WRITINaS. 85 



121 Sp. Loncosilla solenoides, or Anodonta solenoides. Shell 

 elliptic, somewhat swelled, both ends rounded and a little gaping, 

 back horizontal, outside and inside smooth and whitish. Length 1-3, 

 diameter 2-7, axis 2-T of the breadth. 



From the river Jellinghy in Bengal. Small, seldom one inch long. 

 Posterior nerve of the hinge short. 



Addition.— nth N. G. DIANISOTIS. • 



The examination of these Asiatic shells, enables me to afSrra 

 decidedly that the Symphanota hialata of Lea is also a peculiar 

 genus, very different from our Metaptera, nearer to Hiria and 

 Diplasma. I have seen it in Mr. Poulson's cabinet, and ascertained 

 that it has, like Lasmonos, a lamellar tooth on each side, forming a 

 curve as in Diplasma, but these teeth appear simple, not forked, and 

 the two unequal ears, [whence my name] or wings distinguish it as 

 Metaptera from Unio, and Pecten from Ostrea. 



I propose to call it Dianisotis chinensis, as bialatais not a speci- 

 fic but generic character. I could see no cardinal tooth. 



SUPPLEMENT 



On the Fossil Bivalve Shells of the Western Region. 



Almost all the fossil bivalves of the western states from Ohio to 

 Alabama, belong to the great order of Terebratulites or rather 

 Brachiopites, whose animals of Q. Brachiopus were very different 

 from those of the living bivalve shells, having ciliate limbs. My 

 monograph of 1821 contained 23 genera, all new except five [and 

 about 80 species] and five others had already been published in 

 1819 by me in my account of 70 N. G. of animals, Journal de 

 Physique. 



I propose to give an epitome of this monograph which I have not 

 yet seen in print. I possess nearly all the shells. They are found 

 in the secondary strata of limestone, slate and sandstone which 

 extend from Lake Erie to the Gulf of Mexico, in horizontal strata, 

 the limestone being the lowest, and the sandstone the highest, form- 

 ing in many parts hills and ridges from 100 to 500 feet high. They 

 are very rare in the slate. 



Order BRACHIOPIA. 



Animal brachiopus when living, brachiopites when fossil. Shell 

 bivalve, animal within having a bilobed mantle, and two thick ciliate 

 arms or limbs. 



