MORGAN HEBARD 375 



ment are but weakly produced and the coloration is generally 

 paler. Compared with the description of the female of X. 

 sancta, that sex of the present species is slightly smaller, with 

 distinctly shorter tegmina and wings, and differs, as from hamata. 

 in the dorsal abdominal features; also, though agreeing in the 

 paler coloration, the anterior margin of the wing is unicolorous, 

 dark, with no pale marking as described for sancta. 



Type. — cf ; Cincinnati, Santa Marta, Colombia. 4500 feet. 

 July 10, 1913. (M. A. Carriker Jr.) [Hebard Collection, Type 

 no. 427.1 



Description of Type. — Size rather large, form robust. Interocular space 

 about one and one-half millimeters wide, equal in width to interocellar space. 

 Ocellar areas weakly defined, but oceUi strikingly pale. Pronotum much as in 

 festae.^* Tegmina and wings reaching well beyond apices of cerci, the wings 

 have 2 incomplete and 4 complete rami of the ulnar vein.^ Median segment 

 unspecialized. Sixth dorsal abdominal segment with a large median depression 

 heavily clothed with minute hairs, its latero-caudal angles weakly acute-an- 

 gulate produced caudad; seventh segment concealed; eighth with latero- 

 caudal angles more sharply and strongly produced than those of sixth, and 

 embracing the proximo-lateral portion of supra-anal plate to near cereal bases. 

 Supra-anal plate transverse; weakly produced and weakly bilobate between 

 the cerci, this portion strongly subchitinous and fringed distad with fine hairs. 

 Subgenital plate subdeplanate in large mesal portion, rounding sharply into 

 narrow lateral portions which are nearly perpendicular; lateral margins straight 

 to distal third, which is straight, transverse and subchitinous, these margins 

 fringed with fine hairs. At the disto-lateral angles formed by the free margin, 

 spring from the inner surface of the plate elongate chitinous, mobile, cyUndrical 

 arms, when at rest directed across the dorsal surface of the plate above the 

 distal margin (specialized styles) ; the sinistral is slender, extending nearly to 

 the disto-dextral angle, tapering slightly to the shghtly enlarged and roughly 

 rounded apex; the dextral extends slightly beyond the disto-sinistral angle, 

 is moderately stout to a moderate mesal swelling, then slender to its elon- 

 gate clubbed apex, which bears a sharp dorsal thorn with point directed 

 sinistrad. 



Allotype. — 9; same data as type. [Hebard Cln.] 



Description of Allotype. — Agrees with male except in the following features. 



" The general contour of the pronotum appears to be much the same in all 

 the known species. In X. nyctihoroides, however, the even convexity of the 

 inner margin of the narrow pale border gives the pronotum a false appearance 

 of its margin being more evenly convex cephalad. 



'''-' From slight irregularities in the structure of these forks in the small series 

 of the genus before us, it api)ears probable that considerable individual numeri- 

 cal diversity will be found to occur in the species. 



TRANS. AM. ENT. SOC, XLII. 



