CRAYFISHES OE NEBRASKA AND EASTERN COLORADO 
93 
angle larger than anterior but less well defined; abdomen shorter than cephalo- 
thorax; chela large and strong, swollen and heavily punctate, flattened dorso- 
ventrally; inner finger slightly longer than outer; carpus short and thick, deeply 
furrowed above, with small blunt spine on inner surface and two smaller spines 
beneath; third periopods hooked; first pair of abdominal appendages of male thick 
and short, ending in two recurved falciform teeth, upper ones large, strong, corneous, 
inner ones smaller, terminating in mammary-like spine. 
Nebraska localities. — Hall County, 6 miles south of Grand Island; Coon Creek, 
Seward County; Minichaduza Creek, Valentine, Cherry County. 
Colorado localities. — Boulder, Boulder County; Fort Collins, Larimer County; 
Greeley, Weld County; Denver, Denver County; Louisville Junction, Boulder 
County; St. Vrains, Weld County; Empire Reservoir near Deerfield, Weld County; 
Lakeside, Boulder County. 
CAMBARUS (BARTONIUS) ARGILLICOLA FAXON 
Cambarus argillicola, Faxon, 1885, p. 115; Faxon, 1885a, p. 76; Pearse, 1910, p. 19; Hay, 1896, p. 492. 
Cambarus ( Bartonius ) argillicola, Ortmann, 1906, p. 120. 
Male, Form I. 
Body robust; rostrum short, broad, strongly decurved, and well excavated; 
margins raised, slightly convergent; lateral teeth absent, acumen triangular, not 
sharp; post-orbital ridges prominent, without spine; carapace depressed, smooth 
dorsallv, granulate laterally, without lateral spines; cervical groove deep, sinuate, 
broken; areola obliterated in middle, anterior triangular space very small, posterior 
larger but less distinct; chela strong and large, hand nearly smooth, inner border 
serrate or tuberculate, fingers thickly punctate, movable finger deeply excised at 
base, outer finger shorter than inner finger; third periopods hooked; first pair of 
abdominal appendages consisting of two falciform teeth, placed one anteriorly to 
the other, posterior tooth thick and strong, anterior tooth thin, spatulate, and horny, 
inner tooth slightly longer than outer. 
Nebraska locality. — Ponds near State fair grounds, Lincoln, Lancaster County. 
GEOGRAPHICAL DISTRIBUTION 
IN NEBRASKA 
The entire drainage of the State of Nebraska leads to the Missouri River, and 
is everywhere toward the east and southeast except an area north of Chadron, 
where the drainage is to the north. The following tabulation covers the main drain- 
age systems within the State. 
In three cases a river flowing through Nebraska has its source within another 
State. In each of these cases crayfishes have been reported in these streams outside 
of the boundaries of Jfie State. It is reasonable to expect that the same species will 
continue into Nebraska, though there are yet no records of them. 
Missouri River. — The banks of the Missouri River at Yankton, S. Dak., on 
both the Nebraska and South Dakota sides, were studied throughout the month of 
September, but failed to give any specimens. Investigation in midsummer on the 
Nebraska side of the Missouri River at Plattsmouth and for several miles north of 
Nebraska City failed to give the slightest indication of crayfish habitation. A 
44699—27 7 
