1921 J Schmitt: The Marine Decapod Crustacea of California 271 



Distribution. — From Oregon to Gulf of California; Japan; Korea. The 

 locality given by Randall, the Sandwich Islands, is too doubtful to be relied upon 

 (Rathbun). 



Bemarks. — This is the very abundant shore crab which is so common scuttling 

 over the stones of the higher beach. It sometimes contains a large parasitic 

 isopod in its branchial cavities (Baker). 



Biological Survey of San Francisco Bay. — Pachygrapsus crassipes 

 also proved to be a strictly littoral species, apparently less abundant 

 and less widely distributed than Hemigrapsus nudus. Seven speci- 

 mens were collected among the rocks at Point Bonita, and one each, 

 on the Presidio shore, at Sausalito, and on Red Rock. 



Pachygrapsus transversus (Gribbes) 



Grapsus transversus Gibbes, Proc. Amer. Assoc. Adv. Sci., 3, 181, 1850. 

 Goniograpsus innotatus Dana, Crust. U. S. Expl. Exped., pt. 1, p. 345,' 1852, 



pi. 21, fig. 9, 1855. 

 Pachygrapsus transversus Rathbun, H. A. E., 10, 189, 1904; Proc. U. S. 



Nat. Mus., 28, 548, pi. 46, fig. 3, 1910; Bull. U. S. Nat. Mus., 97, 244, 



pi. 61, figs. 2, 3, 1918. 



Pig. 160. Pachygrapsus transversus, J 1 , X %, right cheliped omitted (after 

 Dana). 



Characters. — Carapace about one-third broader than long, lateral margins quite 

 strongly convergent posteriorly from the last lateral tooth; upper surface trans- 

 versely striated, most distinctly so anteriorly, becoming obsolete posteriorly; several 

 of the striae converge toward the lateral tooth on each side; sides with a well 

 marked tooth behind the postorbital; frontal (interorbital) margin distinctly 

 sinuous in frontal aspect. Hands smooth or finely granulate, with a raised, some- 

 times obsolete line on the upper margin, and another on the outer surface, near 

 the lower edge, running to the tip of the immovable finger. Merus of last pair 

 of ambulatory legs with two or three sharply distinct teeth at the posterodistal 

 angle. 



Dimensions. — Length of carapace 15 mm., width 20 mm. (Dana). 



Type Locality. — Key West, Florida. 



Distribution. — California (Kingsley) to Peru; Galapagos Islands; Oriental 

 region; West Africa; Bermudas; Bahamas and Florida Keys to Rio de Janeiro 

 (Rathbun). 



