MCNEILL REVISION OF THE TRUXALINtE OF NORTH AMERICA. l8l 



/ 



The following comparison may help to show that in spite of the dif- 

 ficulty of separating these sub-families there are really very distinct 

 truxaline and cedipodine characters of the head, the pronotum, the 

 tegmina, and the wings. Unfortunately, for classification, a truxaline 

 head does not always go with truxaline pronotum and tegmina. It 

 will usually be found, however, that when one set of characters are 

 strongly presented in one part the opposite set will be no less strongly 

 indicated in the other two regions. Thus, while Acrolophitus and 

 Machaerocera have truxaline heads, they have the typical (jedipodine 

 pronotum, tegmina and wings. I have, accordingly, on account of the 

 preponderance of the last mentioned characters followed Dr. Scudder 

 in excluding these and allied forms from the sub-family under discus- 

 sion. Boopedon, on the other hand, has an cedipodine head, but it 

 too has the characters of the head reversed in the pronotum, tegmina, 

 and wings. There still remain certain genera, as Psoiocssa, Sfirapleura, 

 Aulocara, and their allies, in which the opposing characters of these two 

 sub-families are so evenly blended that in the end it is a somewhat ar- 

 bitrary line that divides the Tnixalince from GidipodiniB. I hope, 

 however, that the character I have chosen (the presence of but one 

 transverse incision which cuts the median carina) will not prove alto- 

 gether unnatural. In accordance with this character I have removed 

 Fso/oessa, Stirapleura and some allied forms, as well as one species 

 of the genus, Aulocara, from CEdipodincB and included them in Trux- 

 alinm- 



CHARACTERS OF THE HEAD. 



TRUXALINE. 



I. — Vertex horizontal or ascending 

 and, when seen from the side, 

 this and the face form an angle 

 rather than a regular curve. 



2. — The front is decidedly oblique. 



3. — The lateral foveolcc are fre- 

 quently absent or invisible from 

 above. 



4. — The antennae are very fre- 

 quently depressed, acuminate, 

 triquetrous, or clavate. 



CEDIPODIN.^i. 



-Vertex declined and, when seen 

 from the side, united with the 

 face by a curved line. 



-The front is sub-perpendicular. 

 -The lateral foveolas are present 

 and visible from above. 



4. — The antennae are very rarely 

 anything but filiform. 



CHARACTERS OF THE PRONOTUM. 



-The width of the pronotum is 

 little greater at the posterior 

 than at the anterior end. 



5.— The width of the pronotum is 

 much greater at the posterior 

 than at the anterior end. 



[Proo, D. a. N. S., Vol. VL] 



[November 23, 1896 ] 



