272 University of California Publications in Zoology [Vol. 23 



Genus Planes Bowdich, Leach 



Carapace smooth, convex, subquadrate or more or less suborbicular ; with a 

 slight notch or tooth behind the acute orbital angle. Anterior edges of ambula- 

 tory legs with a dense fringe of hair. Pelagic crabs, usually found on floating 

 seaweed in the open ocean. 



Planes minutus (Linnaeus) 



Plate 46 



Cancer minutus Linnaeus, Syst. Nat., ed. 10, 1, 625, 1758. 

 Planes minutus Eathbun, H. A. E., 10, 189, 1904; Weymouth, Stanford 

 Univ. Publ., Univ. Ser., no. 4, 63, pi. 14, fig. 44, 1910; Eathbun, Bull. 

 U. S. Nat. Mus., 97, 253, pi. 63, 1918. 



Characters. — Carapace as long as or longer than broad, suborbicular, prac- 

 tically smooth, a few faint lines toward anterior and lateral portions of carapace ; 

 the single blunt tooth behind the postorbital sometimes obsolete. Hand with 

 several oblique lines above and below, and a somewhat obscure longitudinal line 

 on the lower portion of the palm running out on the immovable finger. Anterior 

 edges of ambulatory legs with a dense fringe of hair. 



Dimensions. — Two specimens from off Point Loma, collected by the "Alba- 

 tross, ' ' measure, male : length of carapace 15 mm., width 14 mm. ; female : length 

 of carapace 20 mm., width 19 mm. 



Color. — Color varies from light cream with pinkish tinge and light brown 

 mottled to a very dark nut-brown, occasionally with a bluish cast on carapace 

 and yellowish legs, sometimes with whitish blotches and markings on upper 

 surface. (Murray and Hjort, 1912, pi. 6.) 



Type Locality. — "In Pelagi Fuco natante" (Linnaeus). 



Distribution. — Temperate and tropical seas. Taken at sea, west of Humboldt 

 Bay, in Avalon Bay, Santa Catalina Island, and off Point Loma and San Diego, 

 California (Eathbun). During the month of August, 1918, two small specimens, 

 averaging about a half inch in width, were picked up from the beach at the 

 Scripps Institution, La Jolla, California, by Messrs. P. L. Barnhart and H. J. 

 Snook. 



Genus Hemigrapsus Dana 



Carapace not markedly striated ; with two teeth behind the orbital angle. 

 Outer maxillipeds without a wide rhomboidal gape, only moderately gaping; 

 merus large and not produced at the antero -external angle; palp joined in a 

 notch at about the middle of the distal margin. Abdomen of male does not 

 cover the sternum at its base. 



Key to the California Species of Hemigrapsus 



I. Ambulatory legs hairy. Front with a deep sinus in the middle. Hands of 



chelipeds not spotted with red. 



oregonensis, p. 274. 



II. Ambulatory legs smooth. Front arcuate, very slightly sinuous. Hands of 



chelipeds spotted with red. 



nudus, p. 273. 



