no. 1766. STALK-EYED CRUSTACEA OF PERU—RATHBUN. 539 



acute, and strongly projecting teeth, the firs! of which forms the outer 

 angle of the orbit, and the last is the smallest ; postero-lateral margin 

 concave, bearing one small tooth. Front very narrow, trident ate, 

 middle tooth more advanced and lower than the others. Orbits 

 bordered by six prominent teeth. Maxillipeds exceeding the buccal 

 cavity. Chelipeds nearly equal; wrists and upper borders of cliche 

 spinous; outer surface of palm crossed by five longitudinal, granu- 

 lated ridges; fingers narrowly gaping, black color extending from 

 tips half-way along outer border and whole length of inner border. 

 Legs broad, flat. 

 Width 9 to 14 cm. 



Sand beach, Ancon, February 13. 



Callao, May 18, 1908. 



Taken in fish net, rocky shore, northeast side of San Lorenzo Island, January 11, 

 1907. 



Independencia Bay, taken in 1 fathom at the "Punta Callao" of Isla Vieja, July 

 20, 1907. "Cangrejos" of economic value. 



Distribution. — Ecuador; Peru; Chile. 



CANCER PLEBEJUS Poeppig. 



Plate 38, fig. 1 . 



Cancer irroratus Bell, Proc. Zool. Soc. London, vol. 3, 1835, p. 87; Trans. Zool. 



Soc. London, vol. 1, 1835, p. 340, pi. 4G (part). Not C. irroratus Say. 

 Cancer plebejus Posppig, Arch, fiir Naturg., vol. 2, pt. 1, 1836, p. 134. 



Large and sparsely hairy. Carapace a little shorter and broader 

 than the preceding; also smoother. The ten teeth of the antero- 

 lateral margin are broad, low, and separated largely by closed fissures; 

 the postero-lateral tooth is indicated by a simple notch. Teeth of 

 front and orbits less strong than in C. polyodon; no tooth on upper 

 margin of orbit between inner and outer teeth. Maxillipeds less 

 produced than in C. polyodon, their distal margins more transverse. 

 Chelipeds subequal; two spinous crests on upper surface of chela?; 

 four additional granulated ridges on outer face of palm; dark color 

 restricted to a small area near extremity of fingers and along the pre- 

 hensile teeth; gape very slight. Legs broad, flat, nearly naked. 



Width 10 to 12 cm. 



Callao, May 18, 1908. 

 Distribution. — From Peru to Port Otway, Patagonia. 



PLATYXANTHUS ORBIGNYI (Milne Edwards and Lucas). 



Plate 40, tig. 2. 



Xantho orbignyi Milne Edwards and Lucas, d'Orbigny's Voy. Amer. M£r., 

 vol. (5, pt. 1, 1843, p. 14; vol. 9, atlas, 1847, pi. 7, dg. I. 



Very large. Carapace broad, slightly convex and uneven; antero- 

 lateral margins strongly arched, continuous with margin of front and 



