124 A REVISION OF THE ASTACID. 
52. Cambarus Shufeldtii. 
Plate VII. fig. 1, Plate X. figs. 8, 8’, 8a, 8a. 
Cambarus Shufeldtii, Faxon, Proc. Amer. Acad. Arts and Sei., XX. 134, 1884. 
Male, form I. — Rostrum plane above, margins a little convergent, raised 
into a slight rim from the base to the lateral spies, which are prominent 
and acute; acumen of moderate length, acute, pubescent. Post-orbital 
ridges with anterior spines. Carapace smooth; a sharp spine on the cervi- 
cal groove on each side ; sub-orbital angle prominent, branchiostegian spine 
present. Areola of moderate breadth. Telson bispinous on each side. 
Epistoma triangular, Antennal scale broad. Hand smooth, cylindrical, in- 
fated; fingers slender, incurved at the tips. Carpus smooth, armed with 
a single spine on the antero-inferior border. Meros provided with a single 
spine near the distal end of the superior margin, and two or three below. 
Third segment of second and third pairs of legs hooked. First pair of ab- 
dominal appendages straight, bifid, inner part ending in a straight, acute tip, 
outer part split at the tip into two straight acute points. 
In the second form of the male the hooks upon the thoracic legs are very 
slightly developed, and the first abdominal appendages are less deeply cleft, 
with blunter and less finished tips. The chela is shorter. 
In the female the chela is much shorter, broader, and less cylindrical, the 
abdomen broader. Annulus ventralis a transverse curved ridge, the hind 
side of the ridge concave. 
Length, 19 to 27 mm. 
Locality. — Near New Orleans, La. 
Found with C. Clarkii in the collection made by Dr. R. W. Shufeldt, 
U.S. A., in 1883, now in the U. 8. National Museum. 
This is a minute species closely related to C. Montezume from Mexico. 
Like that species, it has the second and third pairs of legs hooked in the male, 
a condition which normally obtains in no other species known.* —C. Shufeldtit 
is distinguished from C. Montezuma by the presence of a lateral spine on the 
carapace and by the form of the male appendages. In the latter species the 
tips of these appendages are recurved, the inner part flattened at the end 
into a spoon-shaped surface. In C. Shufeldiii the tips of these organs are 
straight, and each of the three points in which they terminate is acute. 
* T have seen two or three abnormal specimens of C. virilis antl C. propinguus with a like disposition 
of hooks on the legs. The same arrangement is found in the three species of Cambaroides from the Amoor 
River basin and Japan. 
