OKTMANN : THE CRAWFISHES OF THE STATE OF PEFNSVLVANIA 399 



cles. The outer margin is rounded, witli no indication of angulation, and entirely 

 lacks the serrations of ('. 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, lint 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 spine.s. 

 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 po-sterior to it. 



Meropodite witli 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 daw 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<troUnu.% more particularly the 

 first pleopods of the male (PI. .\.\.\IX, fig. 10) and the annulus of the female. 



Size. — The largest male of the first form, from Edgewood Park, Allegheny 

 County, is 6<S mm. long; the largest females (same locality and Monaca, Beaver 

 County), are 76 mm. long. 



Color (PI. 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 cijanine-hlue (IX, 3) and china-blue (IX, 13), shading 

 toward the lower margin io j)ale-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 chinorblue shading to pale-blue. Margins of rostrum maroun-purplc (\'III, 9). 

 The hand is ci/anine-blue above, shading toward the lower side to cohaU-blue (IX, 12), 

 azure-blue (IX, 15) and pale-blnc. .\t the base of the dactylopodite there is a good 

 deal of roi/al-purple (VIII, 7). The dactylopodite is ci/aninc-bluc, the outer margin 

 violet (VIII, 10). The finger-tips are orauijc-rcrmilion (\'I f. 12), shading proximally 

 to salmon-color (VII, 17) and whitish. The carpododite ol' the chelipeds is marine- 

 blue, shading to cijanine-bl uc and French-blue (IX, 6). Tubercles and spines of 



