440 PROCEEDIN"GS OF THE NATTOlSrAIi MUSEUM vol. 91 



largely to morphologic, parasitological, and biological investigations : 

 Porter, 1907; Bennati-Mouchet, 1931a, 1931b, 1932a, 1932b; Porter, 

 1936 3; Perez, 1936. 



I should not fail to mention here the modest yet very useful check- 

 list prepared by the late Hermann Luederwaldt, naturalist to the 

 Museu Paulista, at the time curator of the invertebrate collections. 

 In his "Lista dos Crustaceos Superiores (Thoracostraca) do Museu 

 Paulista que Foram Encontrados no Estado de S. Paulo" (1919, p. 

 431) under A. intermedia, the species with which A. odehrechtii had 

 been thought synonymous, he has specimens from "Perus" and "Alto 

 da Serra," localities that I have included in the distribution of 

 A. odehrechtii paulenms (p. 492), and states that the A. laevis from 

 Franca is regarded as an "especie duvidosa." From undoubted dupli- 

 cates of this Franca material received from Dr. H. von Ihering in 

 1915 the tj^pe of a new species, A. franca, has been selected. Dr. 

 von Ihering also sent the National Museum specimens oi A. 0. paulen- 

 sis from Perus. 



The foregoing resume by no means represents a complete bibli- 

 ography of Aegla. It has been assembled for the purpose of setting 

 forth its taxonomic history, indicating its distribution and the sources 

 of my information. More has been done on its parasites than is indi- 

 cated by the works cited above. The genus and its supposedly unique 

 species are usually, if only briefly, referred to in the more compre- 

 hensive general zoological and carcinological texts. 



ZOOGEOGRAPHIC NOTES 



The recorded occurrences of the several species of Aegla, despite 

 the present additions thereto, are altogether too few to admit of 

 more than brief mention of the intriguing speculations that are sug- 

 gested by their geographic distribution. When this is plotted it 

 appears that each of the major tributaries of the largest rivers 

 possesses its own peculiar species (as exemplified in part of A. franca, 

 A. castro, and A. parana). Although in some cases several tribu- 

 taries, where near enough together, may have the same species in 

 common {A. platensis'^ and A. Uruguay ana^), other localities of 



» Porter remarks that Aegla. "laevis" has often been collected in the Chilean provinces 

 Valparaiso, Aconcagua, Coquimbo, and Atacama and records the recent accession of a 

 specimen from the Rfo Maipo, at Santiago. 



* This species is found in the State of Rio Grande do Sul, Brazil ; Uruguay ; and Buenos 

 Aires, Argentina. However, I cannot explain its existence in a locality as far removed 

 as Tucuman, Argentina. A confirmation of this occurrence is needed, as well as collections 

 from the vast stretch of country between Tucuman and the eastern seaboard. 



^ This species seems to be rather generally distributed in the River Plate region and 

 more particularly on both sides of the Rio Uruguay and some little distance up the Parana. 

 For this species we have one tentative record from San Luis, Argentina between 400 and 

 500 miles to the westward of Buenos Aires. As with A. platensis (footnote 4), collections 

 from the intervening stretch of territory, from which we have seen no Aeglas at all, are 

 much to be desired. 



