118 A REVISION OF THE ASTAC1D.E. 



49. Cambarus Putnami. 



Plate V. Jig. 5, Plate IX. figs. 6, 6', 6 a, 6 a'. 



Cambarus Putnami, Faxon, l'roc. Amor. Acad. Arts and Sci., XX. i-Jl. L ss l. 



Male, form I. — Rostrum broad, subexcavated, margins nearly parallel, 

 with a line of ciliated puncta; acumen long, equal in length to the width of 

 base of rostrum, narrow, acute, with a black horny tip and lateral spines. 

 Post-orbital ridges sulcate on external side, inflated at posterior end, armed 

 with a sharp, horny-tipped anterior spine. Carapace long-oval, slightly flat- 

 tened above, heavily punctated, sides rough with ciliated granules ; cervi- 

 cal groove deep, lightly sinuate, broken on the sides just above the small, 

 acute lateral spine ; branchiostegian spine slightly developed ; anterior lat- 

 eral margins angulated, but without sub-orbital spine. Posterior segment 

 of carapace equal in length to half the distance from tip of rostrum to 

 cervical groove. Areola of moderate width, punctated. Abdomen as long 

 as cephalothorax, pleura punctate, telson bispinose on each side. Ante- 

 rior process of epistoma ciliated, triangular, sides convex, marginal e. Basal 

 segment of antennule armed below with an internal ante-apical spine. An- 

 tenna? slender, about as long as the body, scale as long as the rostrum, of 

 moderate width, external border inflated, ending in a sharp spine. Third 

 maxillipeds hairy within and below. Chelipeds stout ; chela large, external 

 margin convex; hand ciliate and punctate above and below (the dots large), 

 swollen above, internal border of moderate length and furnished with two or 

 three rows of depressed ciliated tubercles; fingers gaping at base, at least in 

 large individuals, costate and punctate-lined, external margin of movable 

 finger with depressed ciliated tubercles irregularly disposed in two rows ; 

 tips of fingers incurved, horny. Carpus smooth or faintly tuberculate above ; 

 a large, acute median internal spine, and small proximal and distal internal 

 spines ; beneath, the carpus has a very minute or no median anterior spine, 

 a short and acute external spine. Meros with two superior obliquely placed 

 ante-apical spines; of the ordinary biserial inferior spines only the distal one 

 or two of the outer row are developed. Third pair of legs hooked on third 

 segment Thoracic sterna hairy. Firsl pair of abdominal appendages very 

 long, reaching the base of the chelipeds when the abdomen is flexed, luber- 

 culated on internal border at the base, deeply bifid; rami slender, acute, 

 forming an acute angle with the basal part, the outer slightly recurved, the 



