132 A REVISION OF THE ASTACIDA. 
Oo 
Walla, judging from the number collected at that place by Captain Charles 
Bendire, U.S. A. These specimens are in the U. 8. 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 inalonger 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 suleate, 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. A/amathensis 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 
im 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. Trow- 
bridgii, ete. 
Length, 95 mm. 
2. Astacus ieniusculus. 
Plate VI. fig. 4. 
~ — Astacus leniusculus, Dana, Crustacea U. 8. Explor. Exped., Pt. I. p. 524, Pl. XX XIII. fig. 1, 1852. 
Astacus leniusculus, Strmpson, Journ. Bost. Soc. Nat. Hist., VI. 493, 1857. 
Astacus leniusculus, Wacen, Il. Cat. Mus. Comp. Zodl., No. ILL. p. 94. (After Dana and Stimpson.) 
Astacus leniusculus, Faxon, Proc. Amer. Acad. Arts and Sci., XX. 151, 1884. 
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 the Museum of Comparative Zodlogy (Cat. No. 3655). This is the one figured 
on Plate VI. of this work. 
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