98 A REVISION OF THE ASTACIDAE. 
belong here. The rostrum is mutilated, however, and my identification may 
be erroneous. 
A young female from Lebanon, Tenn., in the Museum of Comparative 
Zoilogy, also seems to belong to this species. 
A dry female in the Museum of Comparative Zodlogy 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. vrilis attains a very large size. I have seen a female specimen which 
measured very nearly 43 inches in length, and Bundy records a specimen 
from Jefferson, Wis., 63 inches from tip of rostrum to tip of telson. 
Tn 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. ammunis. A 
male, form IT., 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. tmmunis. 
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. 
C. virilis and C. immunis 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 O. affnis. 
