Boone, Crustacea, Cruises of "Eagle" and " Ara, 1921-28 79 



Porcellana hoscii J. D. Dana, U. S. Explor, Exped., vol. 13, pt. 1, p. 



421, pi. 26, fig. 11, 1852. 

 Porcellana danae L. R. Gibbes, Proc. Elliott Soc. Nat. Hist., vol. 1, 



p. 11, 1854. 

 Porcellana egregia Guerin-Meneville, Crust. Hist. Cuba, p. 39, pi. 2, 



fig. 1, 1857. 

 Petrolisthes drasiliensis S. I. Smith, Trans. Conn. Arts and Sci., vol. 



2, p. 38, 1869. 

 Petrolisthes galathinus A. E. Ortmann, Zool. Jahrb. Syst., vol. 10, p. 



283, 1897.— C. MoREiRA, Arch. Mus. Nac. (Brazil), vol. 11, p. 



93, 1901. — A. Milne Edwards and Bouvier, Mem. Mus. Comp. 



Zool., vol. 47, p. 289, pi. 1, figs. 1, 2, 1923. 

 Petrolisthes sexspinosus Benedict, Bull. U. S. Fish. Comm., vol. 20, 



pt. 2, p. 133, 1901. 



Genus: PORCELLANA Lamarck, restricted, Stimpson, 1907. 



Porcellana rosamondae, new species. 



Plate 21. 



Name : I take pleasure in naming this little crab in honor of Mrs. 

 William K. Vanderbilt (Rosiamond L. Vanderbilt), a member of the 

 ''Ara" Expedition, 1928. 



Type : Founded on one specimen, dredged in Limon Bay, Panama, 

 January, 1928, by the ''Ara." 



Distribution : Known only from the type locality. 



Material examined : The type. 



Technical description: Carapace 4.4 mm. long, 3.4 mm. wide 

 across the middle region. Carapace convex in both directions ; much 

 the wider on the posterior portion, narrowing anteriorly. Frontal 

 region narrowed, with a short, inconspicuous median tooth depressed, 

 on each side of which and separated by a shallow, U-shaped sinus there 

 is a strong prominent, acute preorbital tooth which projects a little 

 farther forward than the eye. The postorbital tooth is very similar 

 to the preorbital tooth but not quite as long. There is also a strong, 

 acute hepatic tooth, behind which the lateral carina curves around 

 the margin of the carapace. The cardiac region is definitely circum- 

 scribed, but is also crossed by two transverse striae, not unlike those 

 on the remainder of the dorsal surface of the carapace. There are 

 numerous fine, transverse striae forming arcuate lines across the cara- 



