286 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



1918; Martin Doello-Jurado collector; 1 young female; lent by Buenos 

 Aires Museum (9359). Dr. Pedro Rojas collector; 1 ovigerous female 

 (Buenos Aires Mus., 12908); carapace 91 mm. wide; photographs sent 

 by M. Doello-Jurado. 



Argentina; 1897; Bicego collector; 1 young; lent by Mus. Paulista 

 (923). 



PATAGONIA.— D'Orbigny collector; 1 maleholotype (Paris Mus). 



Playa Puerto Piramides; March, 1915; Martin Doello-Jurado col- 

 lector; 1 large male (Buenos Aires Mus. 9185a); examined by Dr. 

 W. L. Schmitt; photographs sent by the collector. 



Genus PARAXANTHUS Milne Edwards and Lucas 



Paraxanthus Milne Edwards and Lucas, d'Orbigny's Voy. Amer. Mer., vol. 6, 

 pt. 1, 1844, p. 18; tj'pe, P. hirtipes Milne Edwards and Lucas. — Nicolet, in 

 Gay, Hist. Chile, vol. 3, 1849, p. 140. 



Carapace narrow, nearly flat except toward the edges; regions well 

 marked; antero-lateral borders long, quadrilobate. Front very 

 prominent, bilobed. Orbits small, oval, directed obliquely upward 

 and forward; margin as in Xantho. Antennules folding very ob- 

 liquely. Antennae in the inner hiatus of orbit, basal article small, 

 scarcely reaching front, next article short, flagellum of medium length. 

 Epistome small and deeply sunken. Buccal cavity much longer than 

 wide, anterior border almost semicircular, arched upward not for- 

 ward. Outer maxillipeds elongate; merus longer than wide, its 

 anterior border so oblique that its inner angle forms a sort of terminal 

 tubercle, and is prolonged noticeably beyond the insertion of the 

 following article which is disposed as in Cancer, that is, situated in a 

 cut of that angle. Fu"st maxillipeds almost like those of Xantho, 

 as are also the chelipeds and legs except that the meropodites of the 

 latter are so short that they do not reach the line of the lateral border 

 of the carapace. The sternal plastron is rather wide anteriorly, 

 strongly narrowed behind; the abdomen is very narrow in both sexes, 

 all segments are distinct in the female, the third, fourth and fifth 

 fused in the male. (Milne Edwards and Lucas.) 



Contains only one species. 



PARAXANTHUS BARBIGER (Poeppig) 



Plates 131 and 132; Plate 133, Figures 1 and 2 



Gecarcinvs barbiger Poeppig, Arch. f. Naturg., vol. 2, pt. 1, 1836, p. 138 (type- 

 locality, shallow brackish bays at the mouths of the Andalien river near Con- 

 cepcion, Chile; type in Leipzig Mus.). — Nicolet, in Gay, Hist. Chile, vol. 

 S, 1849, p. 153. 



Paraxanthus hirtipes Milne Edwards and Lucas, d'Orbigny's Voy. Am6r. Mcr., 

 vol. 6, pt. 1, 1844, p. 19; vol. 9, atlas, 1847, pi. 7bis (type-locality, Valparaiso; 

 type in Paris Mus.). — Nicolet, in Gay, Hist. Chile, vol. 3, 1849, p. 141.— 

 Philippi, Zool. Anz., vol. 17, 1894, p. 265 [2]. 



Paraxanthus barbiger Rathbun, Proc. U. S. Nat. Mus., vol. 38, 1910, p. 583. 



