1007.] 



NATURAL SCIENCES OF PHILADELPHIA. 



177 



Silicate, but strongly punctulate as is the whole facial region ; eyes ovate, 

 quite prominent when viewed dorsad; antennir slightly longer than 

 the head and pronotum together, slender. J'ronotum with the 

 length about equal to the vertical depth of the head ; the caudal width 



Fig. 10. — Prionacris erosa n. sp. Lateral view of tj'pe. 



of the disk contained about one and one-half times in the length of the 



same; cephalic margin obtuse-angulate, caudal margin slightly acute- 



angulate, the immediate apex sharp; median carina moderately arcuate 



in general outline, dentato-scrrate, particularly on the metazona, the 



principal sulcus and the prozonal sulci deeply cutting the crest into 



three parts on the prozona; principal transverse sulci three in number, 



the disk rounding into the lateral lobes on 



the prozona, a distinct but well rounded 



shoulder present on the metazona; lateral 



lobes with the dorsal length about equal 



to the depth, the cephalic and caudal 



margins subparallel for more than half 



their length, ventral margin truncate 



caudad, slightly oblique cephalad. Teg- 



mina about two and two-thirds times the 



length of the head and pronotum together, exceeding the apex of the 



abdomen by slightly less than the length of the pronotum, the greatest 



width being two-thirds the distance from the base; costal margin with 



a slight proximal lobe and arcuate in the distal third, sutural nirirgin 



Fig. 11. — Prionacris erosa n. 

 sp. Wing of type. Nat- 

 ural size. 



