262 University of California Publications in Zoology [ VoL - 23 



Pinnixa occidentalis Eathbun 



Plate 42, figures 5 and 6 



Pinnixa occidentalis Eathbun, Proc. U. S. Nat. Mus., 16, 248, 1893 (part: 

 except specimen from San Diego) ; Holmes, Occas. Papers Calif. Acad. 

 Sci., 7, 89, 1900 ; Eathbun, H. A. E., 10, 187, pi. 7, fig. 4, pi. 9, figs. 6, 

 6a, 1904 (part: except specimens from Cape Fox) ; Weymouth, Stanford 

 Univ. Publ., Univ. Ser., no. 4, text fig. 3, 1910; Eathbun, Bull. U. S. 

 Nat. Mus., 97, 155, text Hg. 96, pi. 34, fig. 1, 1918. 



Pinnixa calif omiensis Rathbun, Proc. U. S. Nat. Mus., 16, 249, 1893; 

 Holmes, Occas. Papers Calif. Acad. Sci., 7, 90, 1900 ; Eathbun, H. A. E., 

 10, 187, pi. 7, fig. 3, 1904; Weymouth, Stanford Univ. Publ., Univ. Ser., 

 no. 4, 56, 1910 (part: except young female from Pacific Grove). 



Fig. 156. Pinnixa occidentalis, J 1 ; a, dorsal view, X 1%; b, chela, X 3% 

 (after Eathbun). 



Characters. — Carapace more or less uneven, about twice as wide as long, 

 occasionally a little more or a little less, with a single bilobed cardiac crest, 

 anterolateral margin marked by a sharp, more or less granulated ridge running 

 from the orbit diagonally outward and backward, crossing the hepatic region, 

 and forming the anterolateral margin of the carapace. Chelipeds stout, setose; 

 palm broad, flat, shining on outside, immovable finger short, markedly deflexed, 

 prehensile edge with a stout tooth in the middle and a small one near the tip ; 

 movable finger much curved, sometimes with a tooth in the middle. Ambulatory 

 legs setose; first pair shorter than the chelipeds, weak; second pair longer and 

 stronger than the first; third pair very long and strong, especially the merus, 

 propodus longer than wide; fourth pair intermediate in length between the first 

 and second; dactyli as long as the propodi. 



Dimensions. — Type, male: length of carapace 9.5 mm., width 19.5 mm.; female: 

 length of carapace 10.5 mm., width 20.5 mm. 



Type Locality. — South of Unimak Island, Alaska. 



Distribution. — Unalaska to Magdalena Bay, Lower California. Shallow water 

 to 238 fathoms. 



Remarks. — Cardiac ridge blunter in female than in male, immovable finger 

 longer, third ambulatory leg shorter and wider, about two and. one-half times as 

 long as wide. Specimens vary in the proportion of length to width of carapace, 

 in the prominence of cardiac ridge, in the direction of the margins of the second 

 abdominal segment of the male, in the length of the immovable finger of the 

 male (Eathbun). Commensal in the burrows of the gephyrean worm Echiurus 

 (Kincaid, from Eathbun). 



Biological Survey of San Francisco Bay. — Pinnix,a occidentalis was 

 only taken outside the bay at three stations, D 5785, 5788, and 5789, 



