272 University of California Publications in Zoology (Vou. 28 
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 Rathbun, H. A. E., 10, 189, 1904; Weymouth, Stanford 
Univ. Publ., Univ. Ser., no. 4, 63, pl. 14, fig. 44, 1910; Rathbun, Bull. 
U. S. Nat. Mus., 97, 253, pl. 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, pl. 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 (Rathbun). 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. 
