THE SPIDER CRABS OF AMERICA 233 



B^. The two dorsal branchial ridges meet outwardly in an acute angle marked 

 by a large spine. Posterior margin of carapace regularly arcuate. 

 Interbranchial space shallower than in tanneri angulatus, p. 247. 



CHIONOECETES OPILIO (O. Fabricius) 

 (CHIONOECETES OPIUO ELONGATUS Rathbun) 



Plates 84 and 85 



Cancer phalangivm O. Fabricius, Favna Groenlandica, 1780, p. 234, Green- 

 land; not Cancer phalangium J. C. Fabricius, 1775. 



Cancer opilio O. Fabricius, K. Danske Vid. Selsk. Skr., nye Saml., vol. 3, 

 1788, p. 182, plate (type-locality, Greenland; type not extant) .^^ 



Chionoecetes opilio Kroyer, Naturh. Tidssk., ser. 1, vol. 2, 1838, p. 249. — 

 Smith, Trans. Conn. Acad. Sci., vol. 5, 1879, p. 41, and synonymy. — 

 Rathbun, Proc. U. S. Nat. Mus., vol. 16, 1893, p. 74, pi. 4, figs. 5-7, and 

 synonymy; in Grenfell's Labrador, 1909, p. 481. — Hansen, Danish 

 Ingolf-Exped., vol. 3, pt. 2, 1908, p. 13.— Parisi, Monitore Zool. Ital., 

 vol. 27, 1916, p. 189. 



Chionoecetes behringianus Stimpson, Proc. Boston Soc. Nat. Hist., vol. 6, 

 Feb., 1857, p. 84 (type-locality, off Cape Romanzoflf, Alaska; cotypes, 

 Cat. Nos. 2031 and 53041, U. S. N. M., Cat. No. 1875, M. C. Z.); 

 Journ. Boston Soc. Nat. Hist., vol. 6, 1857, p. 449 [8]; Smithson. Misc. 

 Coll., vol. 49, 1907, p. 8. 

 ^Peloplastus pallasii Gerstacker, Arch. f. Naturg., vol. 22, pt. 1, 1856, 

 published April, 1857, according to Stimpson (type-locality, Asiatic Sea; 

 type in Berlin Mus.). 



Chionoecetes chilensis Streets, Proc. Acad. Nat. Sci. Philadelphia, vol. 22, 

 1870, p. 106 (type-locality, Chile; type not extant). 



Chionoecetes opilio elongatus Rathbun, Proc. U. S. Nat. Mus., vol. 64, art. 

 14, 1924, p. 3 (type-locality. Sea of Japan, 245 fathoms; holotype, male, 

 Cat. No. 46636, \t. S. N. "m.). 



Diagnosis. — Carapace chiefly tuberculate. Rostrum horizontal. 

 Branchial regions far apart. Lateral margin of carapace exposed in 

 dorsal view as far forward as first pair of ambulatory legs. Mero- 

 podites of legs broadly dilated. 



Description. — Surface covered with a very short pubescence 

 and with scattered, unequal, rugose prominences which are blunt, 

 wartlike, and granulate about the middle but become more acute 

 anteriorly. The larger tubercles end posteriorly rather abruptly in 

 a transverse line across the carapace through the middle of the 

 cardiac region. Gastric region depressed and well separated from the 

 branchial regions. The posterior and postero-lateral margins have a 

 double row of granules, the upper row being widely interrupted at 

 the intestinal region. The antero-lateral marginal row of spines or 

 tubercles is continued to the angle of the buccal cavity. A similar 

 but shorter marginal row crosses the subhepatic and suborbital 



" Dr. K. Stephenscn, of the Zoological Museum of Copenhagen, writes under date of Jan. 29, 1923, that 

 the type is not in that museum. He says: "It is very improbable that any of O. Fabricius's types are 

 preserved. King Christian VIII (who died in 1848) bought his collection or, rather, the remaining parts of 

 it, and our museum includes the royal collection; but there are, unfortunately, no notes on the origin of 

 the material." 



