268 PHYTOPHAGA — CHRYSOMELIDAE. 



-B. Six inner striae on elytra regular. 

 a. Forehead broadly hollowed out. 



Oblong. Bright blue, shiny ; under-side of base of an- 

 tennae and sides of anus (in male narrowly, in female 

 broadly) red-yellow ; tarsi brown. Forehead broadly hol- 

 lowed out in middle. Differing from P. vulgatissima in 

 having sides of thorax somewhat rounded before middle, 

 posterior tibiae of male not curved, and first tarsal joint of 

 male only slightly dilated ; more oblong than P. vitellinae, 

 with antennae longer and stouter, thorax less transverse, 

 with sides rounded before middle, first tarsal joint of male 

 less dilated and much narrower than third. L. If 1. Not 

 uncommon. P. cavifrons, Th. 



h. Forehead not hollowed out. 



Bronze or greenish ; base of antennae and margin of 

 abdomen reddish. Elytra with regular rows of coarse 

 punctures on disc. First tarsal joint of male a little nar- 

 rower than third. L. If — 2 1, Common. 



P. vitellinae, Lin. 



JPrasocuris, 



A, Thorax broader than long. 



a. Thorax dilated before middle, unicolorous dark-green. 



Short ovate, convex, somewhat compressed laterally. 

 Dark green, with a broad yellow-red margin to elytra 

 (sometimes absent). Thorax coarsely and closely punc- 

 tured ; elytra with rows of coarse punctures, the outermost 

 broken into a series of connected punctures. L. 1^ — 1| 1. 

 Kather common. P. aucta, Fab. 



h. Thorax narrowed in front, dark green with yellow- 

 red side border. 



I, Elytra with rows of fine punctures (the outermost 

 broken into a series of connected punctures), without 

 any yellow longitudinal line on disc. 



Oblong, flatly arched. Dark green, side margin of 

 thorax and of elytra broadly yellow-red. L. 1-^ — IJ 1. 

 Common. P. marginella, Lin. 



II. Elytra with rows of coarse punctures (the outer- 

 most broken into a series of connected punctures 

 toward apex only), with a curved yellow-red longi- 

 tudinal line on disc. 



