CAMBARUS. 
Cc} 
Cr 
of hand with two or three rows of depressed ciliate tubercles; fingers costate 
and punctato-lineate, gaping, inner margins with rounded tubercles ;“ mov- 
able finger incurved; carpus punctate above, armed with an acute median 
internal spine and two inferior spines (a large median and a minute external). 
In some specimens there are one or two small antennal basal tubercles. 
Meros smooth without, two obliquely disposed superior sub-apical spines; 
of the biserial inferior spines only a few of the distal ones in each row are 
developed. Distal end of second pair of legs ciliate. Third segment of third 
pair of legs hooked. First pair of abdominal appendages short, reaching to 
the base of third pair of legs, thick, split for a short distance from the tip ; 
outer part longer than the inner; tips recurved, brown and horny. 
Female. — Fingers less widely gaping, outer one ciliate within at base. 
Abdomen broader. Sternum between fourth thoracic legs smooth. Annulus 
ventralis a transverse ridge, thickest in the middle, where there is a rounded 
tubercle divided longitudinally by a sinuous groove. Between the ridge 
and the sternal plates of the fourth pair of legs there is a deep transverse 
fossa. 
Measurements of a male, form I.— Length of body, 60 mm. Length of 
carapace, 30 mm. Length of abdomen, 30 mm. From end of rostrum to 
cervical suture, 20 mm. From cervical suture to posterior border of cara- 
pace, 10mm. Length of rostrum, 10 mm. Breadth of rostrum at base, 
4mm. Length of rostral acumen, 3 mm. Width of areola, 1.5 mm. Length 
of antenne, 60 mm. Length of chela, 25 mm. Breadth of chela, 12 mm. 
Length of movable finger, 17 mm. Internal border of hand, 7 mm. 
In one specimen, a male, form I, the fingers are very much elongated, 
not gaping at base. The length of the internal border of the hand in this 
specimen is 7.5 mm.; the length of the movable finger, 21 mm. 
Locality. —Trondale, Mo. Collected by E. Harrison. 
This species resembles C. rusticus in its general form. The male ap- 
pendages, as well as the annulus ventralis of the female, however, are very 
different from those of any previously described species. The male ap- 
pendages approach in form those of C. propinguus more nearly than any 
other, but in that species these appendages are more deeply bifid, and 
not recurved. 
t The second form of the male is unknown. 
