40 TRUE CRABS OF MONTEREY BAY 



"margin of upper orbital tooth almost transverse, scarcely dentiform. 

 "Lateral teeth separated to their bases, tips spiniform and curved for- 

 "ward ; second, fourth, sixth, and eighth smaller than the others (the 

 "outer orbital tooth reckoned as the first) ; ninth tooth scarcely more 

 "prominent than eighth. No postero-lateral tooth." The alternation in 

 size of the antero-lateral teeth varies with age, being very noticeable in the 

 small specimens and hardly evident in this the largest of the series. It also 

 appears, as stated elsewhere, in the young of other species. The tenth 

 (postero-lateral) tooth is indicated in the present specimen, and less con- 

 spicuously in other younger ones, by a slight gap in the small spines 

 marking the raised postero-lateral margin. "Basal antennal tooth and 

 that of adjoining margin acute," but less produced than in gibbosulus. 

 "Movable part of antennae [nearly] half as long as carapace." In many 

 of the other specimens the antennae fall considerably short of this length. 

 "The outer maxillipeds overlap considerably the basal joint of the anten- 

 nae; merus longer than wide;" obliquely truncated, the inner angle the 

 more advanced, corners rounded. "The palms of the chelipeds have two 

 superior and five external carinae fringed with hair." The superior cariiuc 

 are marked with several small spines besides the hairs. "On the pre- 

 hensile edges of the fingers the dark color runs from the proximal end 

 of the fingers nearly to the tips, but on the outer edges the dark color 

 begins near the middle of the fingers." In the key given by Miss Rathbun 

 in the American Naturalist, jordani falls under the division, "Color on 

 the fingers extending from the tip not more than half the length of the 

 fingers." In the specimen before me and in most of the collection the 

 color extends from the tip of the dactyl distinctly more than half way to 

 its base on the outer edge. 



The measurements of this the largest of the collection and of a series 

 of smaller specimens are here given : 



SEX 



male 

 





 > 



female 



LENGTH 



WIDTH 



INTER-ORBITAL ANTENNAL 

 WIDTH LENGTH 



13.0 mm. 

 8.0 

 8.0 



6-5 

 8.0 



7-5 



5.0 (carrying eggs) 



5-o 



5.0 (carrying eggs) 



