26 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



Description. — Carapace about one-third wider than long, convex, 

 covered with crowded granules of rather uniform size. Front with four 

 acute teeth, the median pair narrower than the lateral, the median 

 sinus shallower than the lateral sinuses. Orbit with two fissures 

 above; ])etween them a strong triangular tooth pointing obliquely- 

 outward. Antero-lateral teeth broad, their outer margins much longer 

 than the inner and conspicuously denticulate; sinuses narrow, semi- 

 circular. Inner suborbital tooth or spine advanced beyond the frontal 

 teeth. Tooth at distal inner angle of merus of outer maxilliped no 

 longer than broad. 



Cheiipeds shorter than in ocellatus; a fringe of hair along the inner 

 side of the upper margin; merus overreaching carapace but little, 

 inner surface granulate, also distal end of upper surface; inner carpal 

 spine broad, having a superior carina, outer spine lacking, upper 

 surface rough; palm with five carinae on upper-outer surface, two 

 carinae at middle of inner surface. Most striking is the broad lower 

 surface of the palm which is crossed by from 20 to 25 or more strong' 

 well separated, granulated striae, the striae breaking into short 

 pieces toward the distal end of the palm. Complementary to this 

 stridulating ridge there is a short, thick, transverse horny ridge on 

 the distal margin of the anterior surface of the merus of the first 

 ambulatoiy leg. Fingers strongW carinated, carinae granulate; 

 movable finger with three longitudinal rows of spinules above, those 

 of the inner row longest and sharpest; prehensile teeth unequal, 

 the larger ones with dentate or lobulate margins. Legs broad, espe- 

 cially last two articles. Dactylus of first pair in adult male falciform, 

 dilated, upper (dorsal) edge deeply grooved, the furrow beginning 

 near the base, its edges then spread out and give a broad, somewhat 

 flattened appearance to the upper surface when viewed from above. 

 Lower edge of first leg heavily furred in the old; swimming feet also 

 margined with hair. 



Color. — Ground yellow thickly mottled with blood-red, reddish- 

 brown or purple dots besides a crescent-shaped median spot and a 

 round or oblong spot near the postero-lateral angle of the carapace. 



Measurements. — Male (61019), length of carapace to end of sub- 

 median spine 85, greatest width of same 109.5, fronto-orbital width 

 49.7, width of front between tips of spines 15 mm. 



Range. — Peru; Chile as far south as Trinidad Channel (Miers); 

 Uruguay; Argentina. South Africa; Japan; China; Australia; New 

 Zealand. On sandy shores. 

 Material examined. — 



PERU. — Independencia Bay; 1919; Robert Cushman Murphy; 1 

 male (54213), from Brooklyn Mus. 



CHILE. — Valparaiso; H. Kroyer collector; specimen in Copenhagen 

 Mus. U. S. Exploring Expedition; 1 male, 1 female, co types of 

 Platyonychus purpureus Dana (4280, 4281, M.C.Z.). 



