132 A REVISION OF THE ASTACII>.F. 



Walla, judging from the number collected at that place by Captain Charles 

 Bendire, U. S. A. These specimens are in the U. S. National Museum. 



Specimens from Sikan Creek, Oregon, differ in some respects from those 

 received from Washington Territory, the sides of the rostrum converging 

 more (as described by Stimpson and Hagen in the Klamath Lake specimens) 

 and ending in a longer acumen. In the specimens from Fort Walla Walla 

 the rostrum is quadrangular, with shorter acumen. In the Oregon specimens 

 the cervical groove is more broadly sulcate, the posterior portion of the 

 cephalothorax broader, the carapace impressed on each side of the median 

 line of the cardiac region and less densely punctate ; the abdomen of the 

 female is more expanded anteriorly, the internal margin of the antennal scale 

 tapers off more gradually from the middle to the tip, and the hand is longer. 



In small specimens of A. Klamathends there is a sharp spine at the 

 antero-interior angle of the carpus ; the rostral acumen is longer, and the 

 post-orbital spines longer and sharper than in the adult. 



In some adult specimens a faint trace of a posterior post orbital spine is 

 to be seen on close examination as a minute brown-horny granule, similar 

 in appearance to the tip of the front end. of the post-orbital ridge. This 

 granule occupies exactly the place of the hinder post-orbital spine of A. Troiv- 

 bridgii, etc. 



Length, 95 mm. 



2. Astacus leniusculus. 



Plate VI. fig. 4. 



Astacus leniusculus, Dana, Crustacea U. S. Explor. Exped., Pt. I. p. 524, PI. XXXIII. fig. 1, 1852. 



Astacus leniusculus, Stimpson, Journ. Bost. Soc. Nat. Hist., VI. 493, 1S57- 



Astacus leniusculus, Hagen, 111. Cat. Mus. Comp. Zool., No. III. p. 94. (After Dana and Stimpson.) 



Astacus leniusculus, Faxon, Proc. Amer. Acad. Arts aud Sci., XX. 151, 1S84. 



Known Localities. — Washington Territory: Columbia River; Puget Sound 

 (Dana, Stimpson). 



One of Dana's types is in the collection of the Smithsonian Institution 

 (U. S. Explor. Exped.. No. 375, Smithson. Inst., No. 2019). The rostrum of 

 this specimen, a male, is mutilated and deformed. Two more male speci- 

 mens are in the same Museum (Cat. No. 2161) without any label indicating 

 their origin.* 



The hands are of unequal size, the left being the larger. Dana says that 



* One of these is now in tin- Museum <>f Comparative Zoulojrv (Cat. No 3655). This is the one figured 

 on Plate VI. of this work. 



