360 Annals of the Carnegie Museum. 



pared with histrio, which latter, as indicated in the synopsis, has the 

 apex of the hind tibiae provided with one to two movable spines, 

 instead of natatory lamellae as in Tridactyliis. 



Rather slender in general form, the folded wings extending fully 

 one-fourth of their length beyond the apex of the abdomen in both 

 sexes. General color rather dark, varied with flavous arranged in 

 patterns much as in the other species of the genus. Penultimate 

 segment of the female abdomen roundly triangulate, the last or apical 

 segment subquadrate, narrowest at its tip, with the apical margin 

 a little advanced at middle, rather heavily clothed with elongate 

 robust hairs; these segments of the male abdomen are quite similar 

 to those of the insect with which comparison is above made, but with 

 the penultimate segment much shorter than in it. 



Length of body, cf , 3.15 mm., 9 , 4 mm.; length to tip of the wings, 

 cT, 4 mm., 9 , 4.7 mm. 



Habitat. — The specimens at hand come from Chapada, Matto 

 Grosso, Brazil, Jan., Mch, May (H. H.Smith); Jacare, Minas Geraes, 

 Brazil, Dec. 11, 1907 (J. D. Haseman). 



The types, cf and 9 , are from Chapada. They are deposited in 

 the Carnegie Museum. 



Genus Rhipipteryx Newman. 



Ripipteryx Newman, Ent. Mag., II (1834), p. 204; Brulle, Hist. Nat. Ins., IX 

 (1835), p. 198; BuRMEiSTER, Handb. Ent., II (1838), p. 742) Blanchard, 

 Hist. Ins., Ill (1840), p. 413. 



Rhipipteryx Serville, Ins. Orth. (1839), p. 316; Saussure, Miss. Mex., Orth., 

 V (1873), p. 354; Biol.-Cent. Amer., Orth., I (1896), p. 208, etc. 



The representatives of the genus Rhipipteryx are confined to the 

 American tropics, where numerous species are known to occur. These 

 insects are quite active and live mostly upon vegetation in damp 

 localities similar to those frequented by the species of both Tridactyliis 

 and Ellipes. Unlike them, however, they do not burrow in the mud 

 and damp sand, but live above ground, as do the grouse-locusts or 

 Tetrigidse among the Acridoidea or Locustoidea. These insects also 

 seem to be rather closely related to the Locustoidea and particularly 

 to the grouse-locusts in some of their structural characters as well as 

 in their habits. This is especially true of the form of the ovipositor, 

 which is composed of four toothed and hooked valves, which work in 

 opposite directions when drilling for ovipositing. 



