46 NEW UNIUNID.K UK THE 



Hah. — Crooked Lake and Little Lakes, New York. James Lewis, M. D. 



My cabinet and cabinet of Dr. Lewis. Mohawk, N. Y. 

 Diam. 1"1, Length 11, Breadth 3-3 inches. 



• Shell smooth, transverse, somewhat inflated, very inequilateral, subangular behind ; 

 substance of the shell thin ; beaks slightly prominent, with numerous closely set, 

 irregular undulations at the tips ; ligament long, thin and dark brown ; epidermis 

 j^ellowish olive, without rays or obscurely rayed, transversely banded ; umbonial slope 

 raised and rounded ; posterior slope carinate, rather wide, with two slightly impressed 

 and three dark lines from the beaks to the margin on each valve ; anterior cicatrices con- 

 fluent, large and slightly impressed ; posterior cicatrices confluent, large and very slightly 

 impressed; dorsal cicatrices placed in the centre of the cavity of tlje beaks ; cavity of 

 the shell rather deep and wide ; cavity of the beaks very shallow, scarcely perceptible ; 

 nacre bluish white or reddish brown and iridescent. 



Soft parts. — Branchial uterus enormously filled the whole length of the outer 

 branchiae, being a light brown. BrancMai very large, inner one the larger, slightly 

 curved below, free nearly the whole length of abdominal sack. Palpi very large, sub- 

 angular, united one-third down the posterior edges. Mantle thickened along the margin. 

 BrancMai opening large, with minute light colored papillte on the edges. Aiial open- 

 ing rather small, brownish, without papillae. Super-anal opening rather small, edge 

 colored, united below for some distance; color of the mass dirty white. 



Embryonic s7«e?night. brown, triangular, with hooks, very like to Lewisii, (nobis). 

 Journ. Acad. Nat. Sci. vol. iv. p. 49, and Obs. on Unio, vol. vi. p. 49. 



Remarks. — Dr. Lewis most kindly sent me many living specimens of all ages of this 

 species which had not been before noticed. It is near to/ragilis, Lam. and Footiana, 

 (nobis), but may easily be distinguished from either. In outline it very closely 

 vesf^mhXeafluviatUis, Sol., but it differs from that species in the undulations of the beaks. 

 Some specimens have obscure green rays, but usually they are without rays. The 

 interior, and especially towards the cavity of the beaks have a thickening, sometimes 

 incrusted, arising probably' from a diseased condition, which is somewhat peculiar to 

 the specimens of this species sent by Dr. Lewis. He mentions in his letter that 

 TJ. radiatus and An. lacvstris are all the species which are found in "Little Lakes." 

 U. complanatus gi'ows in the outlet of Schuyler s T>ake, but not in the lake nor in " Little 

 Lakes. 



Anodonta modesta. pi. 63, fig. 189. 



Testa laevi, elliptic^, subinflata, valde injequilaterali, subemarginata, antice obtuse angulata; valvulis 

 subcrassis, posticiJ crassioribus; natibus subprominentibus, ad apices undulatis ; epidermide olivacea, 

 transverse vittata et obsolete radiata ; margarita caeruleo-alba et valde iridescente. 



Shell smooth, ellipitical, somewhat inflated, very inequilateral, subemarginate. ob- 



