176 University of California Publications in Zoology [Vol.23 



Pachycheles rudis Stimpson 



Plate 33, figure 2 



Pachycheles rudis Stimpson, Ann. Lye. Nat. Hist. N. Y., 7, 76, pi. 1, fig. 5, 

 1859 (1860); Lockington, Ann. Mag. Nat. Hist. (5), 2, 394, 1878; 

 Holmes, Occas. Papers Calif. Acad. Sci., 7, 109, 1900; Eathbun, H. A. 

 E., 10, 168, pi. 6, fig. 6, 1904; Baker, Eep. Laguna Mar. Lab., 1, 102, 

 1912. 



a b 



Fig. 111. Pachycheles rudis, 2; a, dorsal view, natural size (from Stimpson) ; 

 b, telson, X 2. 



Characters. — Chelipeds unequal, with a rugose, irregularly tuberculated and 

 granulated upper surface, provided with a few scattered coarse hairs, of which 

 only a few, if any, are to be found in the gape of the fingers of the larger hand. 

 In the sulci between the granules there is a faint pubescence, which is scarcely 

 evident to the naked eye and which never in the least obscures any of the granu- 

 lations. 



The large, prominent, granulated tubercle on the median distal portion of the 

 palm is low and rounded, about as high as wide at the base, or less; occasionally 

 several longitudinal lines of larger granules are evident behind the large tubercle 

 but they are always more or less inconspicuous and never attain the prominence 

 of those similarly placed in P. holosericus. 



The immovable finger of the larger hand exceeds half the length of the movable 

 one; on the cutting edge of the movable finger, near its base, there is a large, white 

 bilobed or double tooth, while near the upper end of the cutting edge of the 

 immovable finger there is a large tuberculiform tooth. The laminate anterior 

 margin of the carpus is granulate along the edge, giving it a minutely denticulate 

 appearance; rarely if ever is there any suggestion of larger teeth, other than the 

 one comprising the entire laminate portion. 



The telson is composed of five plates; a central (triangular), two terminal, 

 and two lateral. 



Dimensions. — Type, male: length of carapace 10.9 mm., width 11.7 mm. 



Type Locality. — Monterey, California. 



Distribution. — Kadiak, Alaska, to San Diego, California; Lower California 

 (Lockington). 



