84 CALIFORNIA ACADEMY OF SCIENCES. 



subcordate, shorter than the ischiurn, the nntero-internal angle produced; 

 palp joined near the middle of the distal margin of the merus. Dactyls 

 spinulous. Abdomen of the male seven-jointed. 



Type.. O. eximius HOLMES. 



Grapsodius eximius, sp. nov. 



Carapace undulated in front and flattened behind where it is more 

 strongly striated; sides strongly converging posteriorly. The front is 

 over one-half the width of the carapace and has the outer angles more or 

 less projecting and rounded; the anterior edge is thin and minutely 

 granulated; viewed from above it is nearly straight, being slightly convex 

 on either side of the middle where it is a little concave; viewed from in 

 front it sags downward in the center. The orbits are remarkable in being 

 swollen outward so that there is no hollow receptacle, as is usually the 

 case, for the reception of the eyes; the superior orbital margin is marked 

 by a fine ridge extending from the outer side of the front to the postorbital 

 tooth; the inferior orbital margin is marked by a line of granules extend- 

 ing from the lower side of the postorbital tooth to the buccal area. Max- 

 illipeds slender and wide apart. The ischium is much longer than the 

 merusi but not so wide; merus with the outer margin convex and the 

 antero-external angle broadly rounded; the inner margin is straight and 

 the antero-internal angle is produced into a prominent narrow lobe; first 

 joint of the palp strongly convex near the middle of the inner margin; 

 exognath at the base about one-half as wide as the ischium and tapering 

 regularly to the tip which reaches slightly beyond the middle of the merus. 

 Chelipeds subequal; merus short, trigonal, the outer surface transversely 

 striated, the inner margin produced into a laminate expansion which is 

 distally truncated and dentate; carpus with a spine near the middle of the 

 upper margin; hands smooth and inflated; the upper margin of the palm 

 is broadly rounded, but bears a fine ridge; a very fine ridge on the lower 

 side of the outer surface extending upon the pollex; fingers subcylindrical, 

 not ridged or grooved, and armed within with small teeth. Merus of the 

 ambulatory legs dilated and compressed much as in Pachygrapsus cras- 

 sipes, with the upper margins acute and ending in a tooth a little behind 

 the supero-distal angle; the infero-distal angle, in all but the last pair, is 

 dentate; carpal joints with a few small spines near the distal end of the 

 upper margin; propodi with the sides strongly convex and the upper and 

 lower margins spiny; dactyls rather narrow, shorter than the propodi, 

 strongly spinose above and below, and terminating in sleuder claws. The 

 abdomen in the male is widest at the third segment, behind which it tapers 

 to the tip, the sides converging more rapidly towards the posterior end; 

 first segment much longer than the second; third segment about as long 



