1914.] NATURAL SCIENCES OF PHILADELPHIA. 155 



infuscation more or less tessellate or marmorate, linear and punctate 

 in character. 



Distribution. — The present species is only known from two localities 

 in the central portion of the Mexican tableland — Camacho, Zacatecas, 

 and Jimulco, Coahuila. Its vertical distribution is apparently from 

 somewhat below five thousand to about six thousand feet. 



Morphological Notes. — In the male sex the only morphological 

 variation worth noting is that of the degree of arcuation of the 

 margins of the distal excision of the subgenital plate. In the type 

 these margins are straighter than in the others of the sex, but in all 

 they are more or less arcuate toward the angles. In the female sex 

 the ovipositor varies appreciably in robustness without correlation 

 •with the general size. 



Remarks. — The present species and D. caudelli constitute a very 

 distinct section of the genus, having no close relationship to any of 

 the other forms. 



Specimens Examined. — 21; 5 males, 16 females. 



Camacho, Zacatecas, Mexico, November, 1887, (Lawrence 

 Bruner), 5 cf, 14 9. Type, allotype, and paratypes. [Hebard 

 Collection.] 



Jimulco, Coahuila, Mexico, November, (Lawrence Bruner), 2 9 . 

 Paratypes. [Hebard Collection.] 

 Dichopetala caudelli n. sp. 



This species is close to D. tridactijla, but can be readily separated 

 in the male sex by the distinctly longer tegmina, the more normal 

 distal portion of the anal field of the same, the sutural margin of which 

 is but little produced at the apex of the stridulating vein and by 

 the shorter median tooth of the cercus, while in the female the 

 slightly longer ovipositor and acute apices to the lobes of the sub- 

 genital plate enable one to distinguish the present form. The 

 species is similar to tridactyla in the majority of the characters, so 

 we have made our description in large part comparative. When not 

 mentioned specifically, the structure is understood to be similar to 

 that in tridactyla. 



Type: cf ; San Luis Potosi, state of San Luis Potosi, Mexico. 

 (Palmer.) [Scudder Collection.] 



Description of Type. — Size and form as in tridactyla. Head as in 

 tridactyla. Pronotum with the caudal margin of the disk very slightly 

 arcuate, disk itself (indicated by color) broader mesad than in tridac- 

 tyla, the lateral borders of the same less sharply diverging cephalad 

 iind caudad; transverse sulcus severing the lateral borders of the 



