Cope.] "^^ [Dec.lfi, 



Width basis fixed claw of clieles 009 



Lengtli penultimate joint cheles, No. 3. 0175 



Width distal tnd of same 0115 



In the small specimen (No. 2) it appears to be the inferior margin of 

 the cheles which is spiuiferoas. The mesonotum is exposed, and is of 

 moderate width. 



From a fresh water deposit in the Teritory of Idaho, near Hot Spring 

 Mountain. Obtained by Capt. Clarence King's expedition. Museum 

 Smithonian, No. 9779. 



ASTACUS CHENODEKMA, Cope, Sp. nOV. 



This species is represented by the cheles of opposite sides of one in- 

 dividual,^with which I associate with great probability one from the right 

 side of a second. Part of a cephalothorax of a third is associated, but 

 without conclusive evidence of identity, chiefly because of a near re- 

 semblance in the sculpture. 



The first mentioned are remakable for their long slender form, and the 

 absence of all spinous armature from their marguis. The surface of all 

 parts is covered with thickly placed granular tubercles. The external 

 surface is regularly convex on the middle line, the inner convex on the 

 lower portion, the convexity separated from the lower margin by a groove. 

 Upper portion gradually thinned out to the edge. The edges are simply 

 rugose like the sides, though more coarsely so, with small granular promi- 

 nences. The denticulation of the opposed edges of this joint are in- 

 significant, though but a small part of the latter is cleared from the 

 matrix. 



In the second specimen part of the penultimate segment is preserved. 

 Its inferior margin is unarmed, but on the middle of the outer face is a 

 series of short spines rather distantly placed. 



In the third, represented by a cephalothorax, the dorsal suture is regu- 

 larly convex backwards, and the mesonotum of moderate width. The 

 surface is delicately wrinkled by the confluent bases of fine pointed 

 granules directed forwards. They become more scattered on the sides 

 of the cephalothorax. As in the last species there are two spines on each 

 side the front. 



M. 



Length from anterior spine to middle of cross suture 0.0235 



Width between posterior spines 0105 



' ' mesonotum .35 inch from front 007 



Length of last segment of cheles (No. 1) 045 



Width basal part 0173 



" terminal at middle 006 



From Catharine's creek, Idaho ; collected for Capt. Clarence King by 

 .J. C. Schenk, No. 9779, Museum Smithonian. 



ASTACUS BREVIPORCEPS, Cope, 



Species nova. 



Established primarily on three cheles or last segments of the fore limbs; 

 with these I have associated a cephalothorax of one, and abdominal and 



