330 BULLETIN 97, UNITED STATES NATIONAL MUSEUM. 



antero-lateral margin upturned. Surface uneven, covered with 

 granules, two oblique rows of granules on postero-lateral region. 

 Regions well defined, hepatic area depressed. Front rounding down- 

 ward, its posterior width nearly one-half width of carapace, sides 

 forming an arch with the lower margin, a broad median longitudinal 

 furrow. Upper margin of orbit sinuous, sloping backward from the 

 front, outer angle acute, little advanced. Two lateral teeth acute, 

 formed by narrow notches. Infero-orbital crest prominent and 

 tuberculate, as is also the epistomial crest. 



Outer surface of chelipeds rough with granules, arranged partly 

 in rows on the arm, upper edge of arm denticulate, outer and innei 

 edges tuberculate. Inner angle of wrist acute ; palm high and swol- 

 len in the male, upper margin subacute, inner surface granulate at 

 middle; fingers nearly meeting, prehensile edges irregularly dentate, 

 a slight lobe on pollex, an enlarged tooth at base of dactylus. 



Legs rather narrow, somewhat pilose, especially on the anterior 

 (or upper) half of carpal and propodal joints; a blunt tooth on 

 merus joints; dactyli long-pointed; second leg twice as long as-cara- 

 pace. 



Abdomen of male narrow-triangular; last segment little longer 

 than wide. 



Small specimens are more quadrate, less rough, teeth more rec- 

 tangular. 



Measurements. Male (22109), length of carapace 28.3, width 

 of same 35, fronto-orbital width 28.9, posterior w r idth of front 17.1 

 mm. 



Habits. Live in marshes and on the muddy shores of salt lakes, 

 where they take refuge in holes. According to Moreira, 1 when the 

 zone which they inhabit at Lake Maricti, Province of Rio de Janeiro, 

 becomes submerged at high tide, the crabs come up on to the rocks. 



Range. Rio de Janeiro, Brazil (M. C. Z.), to San Matias Bay, 

 Patagonia (M. C. Z.). 



Material examined. 



Montevideo, Uruguay : 1885 ; Mr. Auchevaleta ; 2 males, 1 female 

 (12584). October, 1SSG; W. E. Safford; 5 males, 2 females (12580). 

 1888; Albatross; 7 males (22109). W. Sorensen; received from 

 Copenhagen Mus. ; 1 male (22304). 1897; Bisego, collector; received 

 from II. von Ihering, Mus. S. Paulo; 1 male (47842). F. Felippone; 

 1 male (44G8G). 



Rio Santa Lucia, Uruguay; F. Felippone; 1 male, received Dec., 

 191G, and returned to sender. 



1 Arch. Mus. Nac. Rio de Janeiro, vol. 11, 1901, p. 42. 



