118 BULLETIJSr 9-7, UNITED STATES NATIOWAJ. MUSEUM. 



Dissodactylus mellUae Rathbun, Bull. U. S. Fisli t'onmi., vol. 20, for 19(K) 

 pt. 2 (1901), p. 21. 



Diagnosis. — Edge of front concave. Dorsal ridge nearly as long 

 as antero-lateral distance. Fingers of male gaping. Dactyli of legs 

 1-3 bifurcate for half their length. Male abdomen obtusely angled 

 at sixth segment. Palp of outer maxilliped 2- jointed. 



Description. — Carapace distinctly wider at lateral angles than pos- 

 teriorly; antero-lateral and postero-lateral margins subequal. Dorsal 

 surface nearly naked and smooth, very convex fore and aft, slightly 

 so from side to side. Edge of front concave; antero-lateral borders 

 arcuate and bearing a fine, raised, milled rim, which at the lateral 

 angles curves inward on the carapace at an obtuse and rounded 

 angle, and is continued on the dorsal surface for a distance nearly 

 equal to antero-lateral distance; postero-lateral border with a 



straight rim; poste- 

 rior mai'gin sinuous. 

 Merus-ischium of 

 outer maxilliped sub- 

 spatulate: outer edge 

 of carpus arcuate; 

 propodus quadrate, 

 ^ ■ p widening distally ; 



Fig. 6tJ. — Dissoimct^i-us mei.htak. Oj oltkk mamj.i.i- dactyluS absent. 



FED OF FEMALE (40272), X 23; b, LEG OF PAUATYPE ChelipcdS of malo 



moderately stout; 

 merus and carpus .smooth, propodus roughened with short, oblique 

 ridges, punctate and hairj?^ on their superior-distal side; upper mar- 

 gin convex, lower sinuous: fingers a little deflexed, very narrowly 

 gaping in proximal half, a depressed line of punctae on outer surface, 

 edges entire, tips blunt. Chelipeds of female similar but feebler. 



Legs hairy on edges, compressed; merus joints very wide; carpus- 

 propodus with convex anterior and posterior margins, the propodus 

 strongly tapering, especially in last leg; the dactylus of legs 1, 2, 

 and 3 divided halfway to base, forks slender, curved, acute, an- 

 terior fork twice as long as posterior; dactylus 4 slender, straight, 

 acuminate, furnished with long hair on posterior margin. 



In male abdomen, segments 1 and 2 are partiall}' fused, also 3 to 6 

 inclusive, which have convex margins with a very obtuse angle on 

 sixth segment; seventh subtriangular with convex sides. Append- 

 ages of first segment overlap terminal segment ; basal three-fifths 

 stout and convergent; distal two-fifths slender and divergent. First 

 segment of female abdomen linear, 2. 3, and 4 fused, o and 6 of sub- 

 equal length, seventh broadly triangular, half as wide as sixth, sides 

 sinuous. Eggs numerous, relatively large. 



