Boone, Crustacea, Cruises of ^' Eagle" and "Ara," 1921-28 165 



Portunus xantusi Holmes, Occas. Papers Calif, Acad. Sci., vol. 7, p. 

 71, 1900. — Rathbun, American Naturalist, vol. 34, p. 140, 1900. — 

 Crust. Harriman Alaska Exped., vol. 10, p. 179, 1904 ; Proc. U. S. 

 Nat. Mus., vol. 38, p. 577, 1910.— Weymouth, Stanford Univ., 

 Series No. 4, vol. 49, pi. 12, fig. 35, 1910.— Schmitt, Univ. Calif. 

 Pub. Zool., vol. 23, p. 237, fig. 141, 1921.— Rathbun, BuU. Amer. 

 Mus. Nat. Hist., vol. 48, p. 620, 1923. 



Portunus (Portunus) sayl (Gibbes). 



Plate 55, fig. B. 



Names: Sargassum crab. This species was named in honor of 

 Thomas Say, an American carcinologist, who first described the occur- 

 rence of this species in American waters, mistaking it for the 

 European form, L. pelagica. 



Diagnostic chaeacters: This is a very small species frequently 

 found clinging in Sargassum weed, the yellow and cream color pat- 

 tern of which the crab imitates. 



Type: Say simply records the species as "found in the Gulf 

 Stream." His type was deposited in the Philadelphia Academy of 

 Natural Sciences. Mr. Gibbes' material was taken at Charleston, 

 South Carolina, and is also deposited in this museum. 



Distribution: Found northward in the Gulf Stream as far as 

 "Wood's Hole, Mass.; abundant from Cape Hatteras, N. C, southward 

 throughout the West Indies. 



Material examined: One male taken at Pilon, Cuba, February, 

 1928. One specimen, in Sargassum, 10 miles south of Swan Island, 

 Caribbean Sea, March 23, 1926, by the ''Ara/' William K. Vander- 

 bilt, commanding. 



Color : The upper surface of the crab 's body and legs is irregularly 

 spotted with yellow and cream in imitation of the coloration of the 

 Sargassum. 



Technical description : Carapace elongate oval, relatively smooth, 

 aerolations but weakly defined. The frontal margin has three weak, 

 shallow, broadly rounded teeth in addition to the preorbital teeth 

 which are weak, rounded and only about half as wide as the adjacent 

 pair of teeth. The inferior, inner orbital tooth is a broad, blunt tri- 

 angle, moderately prominent in a dorsal view. There are nine teeth 



