352 Annals of the Carnegie Museum. 



Synopsis of the South American Species of Scapteriscus.' 



A. Tegmina covering more than one-half of the abdomen. 



b. Size very large (length 45-50 mm.). Color pale testaceous, the pronotum 

 with an irregular discal fuscous patch. [Brazil, to Middle Argentina] 



oxydactyius Perty. 



bb. Size smaller (length 25-35 mm.) Color variable, but darker than in the 



alternate category. 



c. Size small, slender (25 mm.); pronotum less than 6 mm. in length; front 



trochanter with the lower outer apexangulate and produced downwards. 



[Brazil] tenuis Scudder. 



cc. Size larger and more robust (28-35 mm.). Pronotum 7 mm. and up- 

 wards in length. Anterior trochanter with the blade variable, 

 but never hooked or produced downwards at the apex. 

 d. Tibial dactyls or fingers distant from each other at base by at least 

 one-half the width of one ot the dactyls. 

 e. Edge of the bare blade on the lower border of the anterior tro- 

 chanter rounded. Tibial dactyls separated by one-hali the 

 width of the lower one. 

 /. Head, pronotum, dorsal edge, and upper half of the outer 

 face of the hind femora rather heavily marked with fuscous. 

 [Mexico, Central and South America, and West Indies] 



didactylus Latreille. 



ff. Head, pronotum, dorsal edge and upper halt of the outer face 



of the hind femora less heavily blotched with fuscous. 



[Paraguay] camerani Giglio-Tos. 



ee. Edge of the bare blade on the lower border of the anterior trochan- 

 ter straight. Tibial dactyl separated by a space nearly 

 equal to the width of the lower one. 

 /. Apical segment of the hind tarsi strongly dilated, fully one-halt 

 as wide as long. Legsstrongly and closely hirsute. [Mexico, 



Colombia, and Brazil] mexicanus Burmeister. 



ff. Apical segment of the hind tarsi less strongly dilated, only 

 about one-third as wide as long. Legs sparsely hirsute. 



[Paraguay, Argentina] borellii Giglio-Tos. 



dd. Tibial dactyls or fingers almost, or quite, touching at their base. 

 e. Tegmina covering nearly the whole abdomen. [Central and South 



America] vicinus Scudder. 



ee. Tegmina covering not more than two-thirds of the abdomen. 



[Brazil and West Indies] agassizi Scudder. 



A A . Tegmina covering only one-half of the abdomen or less. 



b. Tegmina one-half the length of the abdomen, the hind wings shorter than 

 the abdomen, but one-half longer than the tegmina. Trochanter of front 

 legs large, flattened, the sides parallel, rounded at the extremity. [Northern 

 South America] variegatus Scudder. 



5 An occasional depauperate individual of other species may be small, but still 

 possess the structural features credited to those species. 



