296 



ORTMANN — DISTRIBUTION OF DECAPODS 



[April 3, 



(this is the northernmost point, near the Bolivian boundary), Tucu- 

 raan, San Luis, 1 Buenos Ayres. 2 Uruguay. Southern Brazil : Rio 

 Grande do Sul and Santa Catharina, 



As may be seen, the extremities of 

 the range on the Atlantic side, Sta. 

 Catharina and Uruguay, and the 

 southernmost locality in Chili, near 

 Puerto Montt, are also mentioned 

 for the genus Parastacus, and in fact 

 the distribution of Parastacus and 

 yEglea are almost identical (see figs. 

 i and 2), only s£glea seems to ex- 

 tend a little more to the north 

 (Jujuy). This similarity is the more 

 striking, since in both cases the chain 

 of the Cordilleras, which crosses the 

 area of distribution from north to 

 south, has absolutely no effect ; both 

 genera are found on either side of this mountain range, and in 

 the case of dßgleoz Icevis and Parastacus agassizi the identical spe- 

 cies is found east and west of the Cordilleras. This fact is very 

 significant, and important conclusions may be derived from it. 



x 



Fig. 2. 



Distribution of sEglea 

 Icbvís (Latr.). 



C Chorology of the Freshwater Crabs of the Family 

 Potamonid^e (See Figures 3 and 4.) 



bibliography. 



(a) Revisions, more or less complete. 



Milne-Edwards, A. : « Revision du genre Thelphuse " (Nouv. Arch. Mus. 



Paris, V. 5, 1869, pp. 161-191). 

 Henderson, J. R. : " A Contribution to Indian Carcinology " ( Tr. Linn. Soc. 

 London, Ser. 2, Z00L, V. 5, 1893, P- 3%° ff-)- 

 Here a revision of the Indian species. 

 Ortmann, A. E. : " Carcinologische Studien " {Zool. Jahrb. Syst., V. 10, 1897, 

 pp. 296-329). 

 Revision in part, chiefly for the subgenera Potamonautes, Geothelphusa, and 

 the subfamilies Polamocarcinince and Trichodacty iince. 



1 Nobili, G. Boll. Mus. Torino, V. II, No. 265, 1896. 



2 1 have received from the Museum in La Plata specimens that are labeled 

 Ensenada, Rio de la Plata. 



