84 Rev. T. A. Marshall's monograph of 



1. Petalodes imicolor, Wesm. (PL III., fig. 5). 



Petalodes unicolor, Wesm., I. c, ? , pL, fig. 14 (wing) ; 

 Eeinh., I. c, <? ? ; S. v. VolL, Pinac, pi. iv., f. 2 

 (with details of ? abdomen and antenna). 



Rogas compressor, Schaff., F. G., 156. 



Testaceous ; stemmaticum, a patch on the metathorax, aud the 

 antennae towards the apex, fuscous ; valves of the terebra and tips 

 of the tarsi black ; wings subhyaline, stigma yellow, nervures pale 

 fuscous. <y ? . Length, 2| — 3 ; wings ? , 4^ lines. 



Antennae ? 32-jointed, in two specimens (36-jointed in the one 

 described by Wesmael), much shorter than the body ; front with a 

 geminated fovea above the antennoe ; thorax compressed ; meso- 

 thorax flat on the disk, truncated in front of the aute-scuteUar 

 crenate fovea, the sutures subobsolete ; head and thorax granu- 

 lated, not shining ; a smooth space on each side of the scutellum ; 

 metathorax carinated, villose ; abdomen h longer than the head 

 and thorax, segment 1 rectangular, 2h times as long as its width, 

 striolated, with narrow, raised, smooth margins, finely carinated 

 from the base to beyond the middle ; segment 2 eq^^al and similar, 

 except that here begins the lateral compression of the abdomen ; 



3 shorter, narrower, more compressed, striolated at the base, 

 smooth at the apex, as are the following segments, which present 

 a subcvTltriform edge above, and successively diminish in length ; 

 suturiform articulation nearly effaced ; belly similarly compressed ; 

 valves of the terebra flattened, punctulate, scarcely surpassing the 

 anus. Antennae ^ as long as the body, 42-jointed ; abdomen 

 somewhat longer than the head and thorax, parallel at the sides to 

 the end of segment 4, depressed, thence to the apex more convex, 

 and narrower. 



The 2 is easily distinguished by the elongate com- 

 pressed abdomen ; the <? resembles some of the pale 

 species of Rhogas, but may be known by the obsolete 

 suturiform articulation, and the shape of the abdomen, 

 the sides of which are parallel near the base. 



This species has the same habits as Rhogas, attacking 

 young larvae, and undergoing its transformations inside 

 their dried bodies. A dozen or more males and females 

 were bred in this manner from larvse of Pygcera pigra, 

 Hufn., taken by Norgate in the New Forest. These 

 larvae perished after attaining the length of about 



4 lines, and one Petalodes emerged from each through a 

 hole in the posterior dorsal segments of the hardened 



