172 



RATHBUN 



horns slender, divergent, their outer margins almost longitudinal, their 

 length along the inner margin about one eighth of the entire length of 

 the carapace. Supraocular eave extending laterally not quite so far as 

 in O. gracilis. Postocular spine narrow, as in O. gracilis, and directed 

 a little more forward than in that species. The interantennular spine is 

 curved a little more forward than in O. gracilis. Eyes a little stouter than 

 in that species. Basal segment of antenna armed along its outer margin 

 with one stout blunt subterminal spine and three small spines, one of which 

 is at the anterior angle, and along its inner margin with one or two 

 tubercles. Outer maxillipeds as in O. gracilis. Lower surface pubescent. 



Chelipeds of the female of moderate size, one and a half times as long 

 as carapace, subequal, shaped much as in O. gracilis. Inner surface of 

 merus bordered by short blunt spines. Propodus slightly longer than 

 merus, fingers and palm subequal, margins of palm subparallel, fingers 

 fitting close together, denticulate. Ambulatory legs slender, diminishing 

 gradually in length from the first to the fourth pair, the third pair being 

 the length of the female cheliped. The dactyli are contained about one 

 and a third times in their propodi. Chelipeds and ambulatory legs covered 

 with long yellow hair, mixed with shorter and finer hair. 



Dimensions. — Length of carapace and rostrum 26.5 mm., width of 

 carapace 19.6 mm., width between tips of postorbital spines 13 mm., 

 length of horn measured along the inner edge 3.4 mm., distance between 

 tips of horns 3.5 mm. 



Type locality. — North of Rat Islands, Aleutian Chain, 270 fathoms 

 {Albatross station 3785), one adult female. 



This species, by reason of the character of its orbits, maxillipeds, and 

 trunk-legs, falls into the genus Oregonia, but differs from O. gracilis in its 

 spreading horns, greater anterior breadth, different ornamentation of the 

 basal antennal segment, etc. 



Genus Dasygyius Rathbun. 

 DASYGYIUS TUBERCULATUS (Lockington). 

 Plate X, figs. 3, 3a. 



Distribution. — From Alamitos Bay, Cali- 

 fornia, to Panama Bay, including Gulf of 

 California; 4 to 33 fathoms. 



A fine series of specimens of this species 

 was collected in San Diego Bay, 6 fathoms, 

 by the Albatross (station 3620) ; the largest 

 V\c,. ()2. Dasygyius ttibercuiatus. «. male mcasuTCS 23 mm. long and 17.2 mm. 



Station 3030. a. Maxilliped, much en- 



larged. ^. Sideview of carapace (X li)- WidC, 



