NO. 1187. 



TWO NEW SPECIES OF CRAYFISH— HAT. 



123 



Abdomen longer than the cephalothorax ; pleurae punctate; telson 

 rounded behind, anterior segment with four or more spines on each 

 side of the i)osterior border. Antenna? shorter than the cephalo thorax; 

 anteunal scale shorter than the rostrum, broadest near the middle, tip 

 convex, inner margin rounded. Epistoma broader than long, sides 

 convex, anterior angle denticulate. Third maxillipeds hairy on their 

 inner faces. Chelipeds 

 moderately strong: 

 chelte inflated, punctate 

 above and below ; inner 

 margin of hand longer 

 than the fingers; outer 

 finger short, nearly 

 straight, inner finger 

 rather strongly in- 

 curved at tip ; both fin- 

 gers strongly ribbed 

 above and jirovided on 

 their cutting edges with 

 two or three large teeth 

 and numerous serra- 

 tions. Thoracic ster- 

 num hairy. Annulus ventralis prominent, subcircular, the wall bitu- 

 berculate and thin in front, broad and low behind. The fissure is very 

 sharply bent to one side just within the anterior wall and is lost, but 

 an accessory branch, separated by a thin wall from the first, bends back 

 to the middle of the annulu's and emerges at the x)osterior angle. The 

 appendages of the first abdominal somite are not developed. 



A single specimen about 2 inches in length. 



As no specimen of the male of this species has yet been collected, it 

 is impossible to say with certainty where this species belongs. In gen- 

 eral appearance it is very unlike any other J^orth American species 

 yet discovered. In the rounded, toothless rostrum and the peculiarly 

 shaped chelte it resembles somewhat some of the South American 

 Parastacinse, bat the resemblance stops there. The closest relatives 

 will probably be found to be some of the species of the second group of 

 Faxon, and of these Cambarus ciibensis approaches it most closely in 

 appearance. 



Fig. 2. 



NOS. 1, 2, CAKAPACE ; 'So. 3, CHELA; NO. 4, ANNULUS 

 VENTRALIS. 



