Vol. 32, pp. 5-6 February 14, 1919 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



THREE NEW SOUTH AMERICAN RIVER-CRABSj 

 BY MARY J. RATHBUN. 



The National Museum has acquired in recent years through 

 the activities of the University of Michigan three new species 

 of crabs from the fresh waters of the northernmost countries 

 of South America. 



Pseudothelphusa martensis, sp. nov. 



Holotype. — Adult male, Cat. No. 53311, United States National Mu- 

 seum. Collected in the Santa Marta Mountains, Colombia, by M. A. 

 Carriker, 1914, and given to the National Museum by the University of 

 Michigan. 



Measurements. — Male holotype, length of carapace on the median line 

 28.5 mm., width of carapace 52 mm., width between outer angles of orbits 

 29.3 mm., width of front above, between the eyes, 14.6 mm., width of 

 front below 11.7 mm. 



Description. — Front of carapace between the eyes not carinated above 

 but bounded by a definite line roughened by low, flat tubercles. Outer 

 margin of merus of third maxilliped forming an angle with the anterior 

 margin. The species is allied to P. bouvieri, 2 from Santa Fe de Bogota, 

 but differs as follows: Front considerably wider in proportion to width 

 of carapace, upper edge straighter, lower edge more deeply sinuous, and 

 quadrilobate instead of trilobate, all the lobes reaching downward to the 

 same transverse line; orbits more elongate in proportion to height; epi- 

 gastric lobes nearer front and emphasized by a deep, transverse thumb- 

 nail impression anteriorly; lateral cervical tooth larger, cervical suture 

 continued quite to base of tooth; merus of outer maxilliped much smaller 

 than in P. bouvieri, and much narrower than ischium; exognath reaches 

 two-thirds length of ischium; margins of male abdomen more convex; 

 appendages of first segment lack the large lobe on outer side in distal half. 



Pseudothelphusa iturbei, sp. nov. 

 Holotype.— Adult ma le, Cat. No. 53310, United States National Mu- 



i Published by permission of the Secretary of the Smithsonian Institution. 

 2Rathbun, Proc. U. S. Nat. Mus., vol. 21, 1898, pp. 518, 533 & 537, text-fig. 9; Nouv. 

 Arch. Mus. Hist. Nat., Paris, vol. 7, 1905, pp. 274, 287, 289, pi. 13, fig. 5, text-fig. 81. 



2— Proc. Biol. Soc. Wash.. Vol. 32,1919. (5) 



