ORTMANN: THE CRAWFISHES OF THE STATE OF PEFNSYLVANIA 399 
cles. ‘The outer margin is rounded, with no indication of angulation, and entirely 
lacks the serrations of C. carolinus, the punctures producing the latter forming in 
this species no regular row. 
The carpopodite is much more spinous. The large spine of the inner margin is 
well developed. The spine in the middle of the anterior margin of the under side 
is tuberculiform, and the tubercle at the lower articulation with the hand is insig- 
nificant. But there always are additional distinct spines, which are well developed, 
although smaller than the large spine of the inner margin. <A spine on the proxi- 
mal end of the inner margin is always present, and also a spine between the large 
spine of the inner margin and the anterior tubercle of the lower side. (If the latter 
spine is missing, the claw has been regenerated.) Often there are other spines. 
The proximal spine of the inner margin may be double, and there may be one or 
several spines or tubercles near the base of the large spine of the inner margin, 
anterior or posterior to it. 
Meropodite with the distal tubercles of the upper margin very indistinct, gener- 
ally missing. The outer lower margin is formed by a smooth keel, which has in 
most cases only one small tubercle near the distal end, which may be obsolete. In 
rare instances there are two tubercles. If there are more, the claw has been regen- 
erated. The inner lower margin has a row of 6-12 spiniform tubercles; if less, 
the claw has been regenerated. 
All the other organs are similar to those of C. carolinus, more particularly the 
first pleopods of the male (Pl. XX XIX, fig. 10) and the annulus of the female. 
Size. —The largest male of the first form, from Edgewood Park, Allegheny 
County, is 68 mm. long; the largest females (same locality and Monaca, Beaver 
County), are 76 mm. long. 
Color (Pl. B, Fig. 4).—In specimens with fresh shells the middle of the cara- 
pace and abdomen is of a beautiful marine-blue (Ridgway, 1886, IX, 2); the hepatic 
and branchial regions are cyanine-blue (IX, 3) and china-blue (IX, 13), shading 
toward the lower margin to pale-blue (IX, 16). The marine-blue of the abdomen is 
restricted to the anterior parts of the segments; the posterior parts and the epimera 
are china-blue shading to pale-blwe. Margins of rostrum maroon-purple (VIII, 9). 
The hand is cyanine-blue above, shading toward the lower side to cobalt-blue (LX, 12), 
azure-blue (IX, 15) and pale-blue. At the base of the dactylopodite there is a good 
deal of royal-purple (VIII, 7). The dactylopodite is cyanine-blue, the outer margin 
violet (VII1, 10). The finger-tips are orange-vermilion (VII, 12), shading proximally 
to salmon-color (VII, 17) and whitish. The carpododite of the chelipeds is marine- 
blue, shading to cyanine-blue and French-blue (IX, 6). Tubercles and spines of 
