CAMBAEUS. 31 



"Long. 1.95. Cephalothorax .6. Thorax .25. Abdomen .8. Cauda .3. 

 Antenna .9. Chela .6, latitat!. .2, forceps .3. 



" Habitat in Georgia inferiore, in aquae purae rivulos qui inter colliculos 

 arenosos {sand-hills) currunt." 



The Philadelphia type agrees well with Le Conte's description. The 

 chela, however, under close inspection, is seen to be covered with obsoles- 

 cent, ciliate, squamous tubercles, and the areola is moderate rather than 

 wide. The fingers are ciliated along their inner margins. There is a single 

 lateral spine on each side of the thorax, three spines on the right side of the 

 telson, four on the left side. Carpus with two prominent spines on the inside, 

 and one below, near the exterior articulation of the hand. The sides of the 

 rostrum converge but little from the base to the lateral spines. The acumen 

 is long. The sexual appendages are figured by Hagen. The measurements 

 of this specimen (a male, form I.) are these : — 



Length, 47 mm. Carapax, 22 mm. Abdomen, 25 mm. From tip of ros- 

 trum to cervical groove, 16 mm. From cervical groove to posterior border 

 of carapace, G mm. Length of rostrum, 8 mm. ; acumen, 3 mm. Width of 

 rostrum at base, 3 mm.; between lateral spines, 2 mm. Width of areola, 

 1.5 mm. Length of chela, 15 mm. ; breadth of do., 4 mm. 



It resembles C. Lecontci in general appearance, the shape of hand, and 

 number of lateral thoracic and telson spines. The first pair of abdominal 

 legs are different, resembling those of C. spiculifer, but different from either. 

 The sides of the rostrum are more nearly parallel than in G. Lecontci, in 

 this respect resembling C. vermtus. It seems to be a very much smaller 

 species than its near allies. 



9. Cambarus pubescens. 



Plate I. fig. 3, Plato VIII. fins. In, la. 



Cambarus pubescens, Faxon, Proc. Amer. Acad. Arts and Sri., XX. 109, 1S84. 



Male, form II. — Rostrum long, triangular, sides subparallel at the base. 

 then converging towards the lateral spines, which are evident ; slightly de- 

 pressed above at the base, subplane, with raised margins ; ciliated, especially 

 on the acumen; acumen long, pointed. Post-orbital ridges with anterior 

 spines. Carapace cylindrical, fore border angulated behind the antennas, 

 punctate above, slightly granulated on the sides, with one lateral spine on 

 each side. Cervical groove ciliated. Cardiac region short (much less than 



