98 A REVISION OF THE ASTACID^E. 



belong here. The rostrum is mutilated, however, and my identification may 

 be erroneous. 



A young female from Lebanon, Term., in the Museum of Comparative 

 Zoology, also seems to belong to this species. 



A dry female in the Museum of Comparative Zoology is labelled " Lake 

 George, L. Agassiz " ; and there are also three dry specimens labelled 

 " Montreal ? Mr. Hunt." Considering the ease with which labels of dry 

 specimens get misplaced, it is hardly safe to give Lake George and Montreal 

 as localities for this species until confirmed by further exploration. 



C. virilis attains a very large size. I have seen a female specimen which 

 measured very nearly 4^ inches in length, and Bundy records a specimen 

 from Jefferson, Wis., Gf inches from tip of rostrum to tip of telson. 



In specimens from Laramie the lateral spines of the rostrum are obsoles- 

 cent, and the rami of the male appendages are more strongly curved than in 

 the typical form. In these respects the specimens .approach C. imuiunis. A 

 male, form II., from Ellis, Kansas, in the Peabody Academy of Science at 

 Salem, has the areola reduced almost to a line in the middle, and the short- 

 ness of the carapace behind the cervical groove shows another approach to 

 C. immmm. 



In specimens from Irondale, Mo., the cephalothorax is more cylindrical 

 than in the type form, the areola wider in the middle (2 mm. in a specimen 

 68 mm. long, whereas in a specimen of the same size of the typical form it 

 is about 1 mm.), and the tubercles on the internal border of the hand and 

 on the movable finger are less prominent and more heavily ciliated. The 

 sides of the rostrum are nearly parallel, with small acute lateral teeth. The 

 carpus has the additional inferior spine as in Hagen's variety A. But I see 

 no difference of sufficient importance to be deemed of specific value. 



G. virilis and C. immtmis are two of the Western species of crayfish es- 

 teemed as food. They are sometimes sent to the New York market from 

 Milwaukee and other Western cities, but the species commonly found in the 

 Eastern markets is C. ujfinis. 



