MORGAN HEBARD 169 



Cahita nahua (Saussure) (Plate VI, figures 10, 11 and 12.) 



1.S6S. I techno pier a nahua Saussure, Rev. ct Mag. de Zool., (2), xx, p. 3.5(>. 

 [cf, 9 ; [Orizaba, Vera Cruz,] Mexico.] 



Venvidio, IX, 2, 1918, 1 cf .^"^ 



The present material differs only from the mor(> del ailed 

 description given by Saussure in 1870, in having the head 

 immaculate, lacking "unc grande tache brune sur le front entre 

 les antennes." 



As the insect is one of the most distinctive forms of the Group Ischnopterae, 

 we note the following additional features for the male. Interocular space 

 slightly less than half as broad as that between the antennal sockets, showing 

 subobsolete impression. Maxillary palpi with third joint three-quarters as 

 long as fifth; fourth half as long as third, expanding strongly, so that the 

 oblique distal and ventral margins are equal in length; fifth joint very large, 

 apex bluntly rounded, entire distal surface deeply concave, fringed along tlie 

 dorsal margin with hairs. Median segment with two meso-cephalic adjacent 

 tufts of agglutinated hairs. Plate at base of each cercus produced in a moder- 

 ately curved spine, the sinistral reaching to near the median point of the 

 anal chamber, the dextral decidedly shorter, Subgenital plate with lateral 

 portions well supplied with fine hairs both internally and externally, margin 

 of distal portion armed with an even fringe of closely placed, elongate, chaeti- 

 form spines, directed dorsad, and having a brush-like appearance as these 

 spines are partially agglutinated. 



Measureineiitsi {in millimeters) 



Length of Length of Width of Length of Width of 

 body pronotiun ])ronotiun tegmon tegnioi! 



Motzorongo, Vera Cruz .12.1 .i . 1 4.2 11.8 3.8 



Motzorongo, Vera Cruz .12.5 3.1 4.3 11.8 3.7 



C.uernavaca, Morelos. . . 14.7 3.8 5 14 4.0 



Ven\idio, Sinaloa 14.3 3.8 5.2 14.8 4.8 



One of the a{hilts and the immature indivi(hial from the 

 State of Vera Cruz lack the heavy distal spiiu^s of the ventro- 

 cephalic margin of the cephalic femora. We are unable to 

 account for this, which though apparently having neither 

 generic or specific significance, constitutes a differentiation of a 

 character usually indicating generic distinction. 



'" Tlierc are also before us two males from Motzorongo, X'cra Cruz, taken 

 in February 1892, by L. Bruner, in the author's collection; one inmuiture 

 mal(! froiu Vera Cruz, taken by the Rev. T. Hej'dc in the same collection, and 

 one male from Cuernavaca, Morclos, taken in November, 1905, l)y W'm. 

 Scluuis, in the United States National Museum. 



TKANS. AM. ENT. SOC, XLVUI. 



