t 



THE GEAPSOID CBABS OF AMERICA. 259 



Genus GRAPSODIUS Holmes. 



Grapsodius HOLMES, Occas. Papers California Acad. Sci., vol. 7, 1900, p. S3; 

 type, G. eximins Holmes. 



Carapace striated above, with the sides converging behind, and 

 armed with a single tooth behind the postorbital. Front broad, not 

 defiexed, but with the median portion depressed. Eye-peduncles 

 short. Orbits with the posterior surface bulging outwards instead 

 of concave. Antennules and antennae unknown. Maxillipeds nar- 

 row, widely gaping, and devoid of an oblique piliferous ridge; merus 

 subcordate, shorter than the ischium, the antero-internal angle pro- 

 duced ; palp jointed near the middle of the distal margin of the merus. 

 Dactyls spinulous. Abdomen of the male seven- jointed. (Holmes.) 



Known only from the type-species. 



GRAPSODIUS EXIMIUS Holmes. 



Grapsodius eximius HOLMES, Occas. Papers California Acad. Sci., vol. 7, 

 1900, p. 84, (type-locality, San Diego; type in Mus. Univ. Cal.). 



Diagnosis. Sides converging behind, unidentate. Posterior sur- 

 face of orbit bulging outward. Maxillipeds slender. 



Description. Carapace undulated in front, flattened behind where 

 it is more strongly striated; sides strongly converging posteriorly. 



Front over half width of carapace, outer angles more or less project- 

 ing and rounded; anterior edge 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; superior margin marked by a fine ridge; inferior margin by a 

 line of granules from the postorbital tooth to the buccal area. 



Maxillipeds slender and wide apart. Ischium much longer than 

 merus, but not so wide ; merus with outer margin convex and antero- 

 external angle broadly rounded, inner margin straight and antero- 

 internal angle produced in a prominent narrow lobe. First joint of 

 the palp strongly convex near the middle of the inner margin. Exog- 

 nath at the base about half as wide as ischium and tapering regularly 

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



Chelipeds subequal. Merus short, trigonal, outer surface trans- 

 versely striated, the inner margin produced into a laminate expansion 

 which is distally truncated and dentate. Carpus with an inner spine. 

 Hands smooth, inflated; upper margin of palm broadly rounded, but 

 bears a fine ridge; a very fine ridge on the lower side of the outer 

 surface extends upon the pollex. Fingers subcylindrical, not ridged 

 nor grooved, and armed within with small teeth. 



