94 CALIFORNIA ACADEMY OF SCIENCES. 



Pinnixa (Scleroplax) granulata (Rath.). 



■Scleroplax granulatus Eathbun M., Proc. U. S. Nat. Mus., Vol. XVI, 

 1893, p. 251. 



Carapace strongly convex, curving downward towards all the margins; 

 «ides rounded. Front very narrow (not one-fifth the width of the cara- 

 pace), somewhat produced, almost transverse (slightly convex in the 

 •center), and uniformly convex above, having no median or transverse 

 groove. No prominences behind the front. Median region not marked by 

 :sulci. Surface of the carapace more or less granulated anteriorly and near 

 the margins, elsewhere smooth and punctate. Antero-lateral margin 

 ■defined by a finely granulated ridge which runs parallel to the inferior 

 margin of the carapace until very near the point, where it disappears, 

 when it bends toward the lower margin but is not continued far enough 

 to meet it. Orbits nearly circular. Antennules nearly transverse. Max- 

 illipeds nearly longitudinal; merus broad, not curved; second joint of the 

 palp narrow and longer than the merus, tapering gradually to its rounded 

 tip; third joint rather narrow, spatulate, joined near the base of, and 

 slightly exceeding the preceding joint; both of the last joints are grooved 

 on the outer surface and fringed with long hair. Chelipeds of the female 

 small, granulated, shorter than the following legs; hands pubescent, of 

 moderate size, margins rounded; palm more or less inflated; pollex nearly 

 longitudinal; dactyl curved. Ambulatory legs slender, compressed, not 

 markedly unequal; dactyls very long, slender, almost straight, about 

 •equaling the propodi in all the pairs, and furnished with long, sharp, 

 -corneous tips; the first pair is somewhat smaller than the second, which 

 is smaller than the third pair. Abdomen of the female smooth and 

 shining. 



Length of carapace, female, 7.75 mm.; breadth, 10.75 mm.; length of 

 "third ambulatory leg, 11 mm. 



Ensenada, Lower California (Miss Rathbun); Bodega 

 Bay, Calif.! 



The genus Scleroplax cannot be sustained, I believe, 

 as some undoubted Pinnixas have a hard carapace and 

 there are transition forms between granulata, in which 

 the third pair of ambulatory legs is but little larger 

 than the others, and the species in which the third pair 

 is greatly developed. There are similar gradations 

 between the very wide forms like longipes and the nar- 

 rower species like granulata and faba. 



