340 PROCEEDINGS OF THE ACADEMY OF NoV. 



apparent wings at hand. In addition they are shghtly more robust, 

 with shorter and more trmicate pronotum than the specimens re- 

 corded by Rehn from Para, Brazil,^ ])ut agree fully in these respects 

 with the original description, as well as with specimens from Chan- 

 chamayo, Peru, before us, which show even greater tegminal reduc- 

 tion than the Para individuals, 



Labidura riparia (Pallas). 



1773. Forficula riparia Pallas, Reise Russischen Reichs, II, Buch 2, Anhang. 



p. 727. [cf ; shores of Irtysch (Irtin) River, western Siberia.] 



Rio de Janeiro, Brazil, 1 cf . 



Labidura xanthopus (Stal). 



1855. Fiorficdisa] .rantJwpus St&I, Ofv. Vet. Akad. Forh., XII, p. 348. 

 [Rio de Janeiro, Brazil.] 



San Ignacio, Misiones, Argentina, III and IV, 1 9 . Tucuman, 

 (border of Rio Chilimayo), Argentina, 2 9 . Icano, Santiago del 

 Estero, Argentina, 2 9 • 



The females from the last locality alone have the wings visible 

 and fully developed. These have the pronotum proportionately 

 smaller and distinctly more slender than the others. 



LABI ID AE. 

 SPONGIPHORINAE. 

 Purex formosus ntw species. (Plate XIII, figs. 1 and 2.) 



This handsome species appears to be widely distinct from the 

 other known forms of the genus, agreeing in certain features of 

 coloration more closely with hrunneri (Bormans), from the upper 

 Amazon, than with the others. 



The male pygidium, though more highly specialized and much 

 more declivent, recalls the type developed in Vostox brunneipennis 

 (Serville), (see plate XIII, fig. 3). 



The male forceps show a much weaker curvature than is devel- 

 oped in several species of Purex and are distinctive in having a heav}^ 

 median and smaller uncinate proximal tooth on the ventro-internal 

 margin. 



Type — cf ; Gourdonville, French Guiana. October. [Paris Mu- 

 seum.] 



Size medium, form slender. Head depressed, broadly convex 

 surface between eyes showing two small and weak impressions, 



* As Pnalis scudderi with a query. Trans. Am. Ent. Soc, XLII, p. 218, (1916). 



