118 THE CANADIAN ENTOMOLOGIST. 



than Yz the length of thorax down the median axis. Wing-pads 

 extend half way to third abdominal segment. Beak brownish, with 

 short pubescence. Legs pure white, antennae no larger than before, 

 but fringed with short cilia. Tarsi of first two legs one-jointed ; those 

 of third leg two-jointed, otherwise legs as before. 



In comparing the various larval stages one is struck by marked 

 increase in the size of the eyes relative to the size of the head as 

 development proceeds. Another point is of great theoretical interest. 

 As is well known, there exists throughout the group an extraordinary 

 sexual dimorphism, such that the uninitiated might be led to class 

 males and females of the same species in different families, so great 

 is the dissimilarity in structure. It is of interest to note that the 

 larval stages up to the last instar, with respect to those structures 

 (palse, frontal fovea, asymmetry of abdominal segments, etc.), that 

 exhibit this dimorphism, are entirely of the female type,^ The writer 

 has dissected the much larger Arctocorisa harrisii Uhl. during the last 

 moults, and has found the same thing to be true. A specimen in 

 the fifth instar just ready to moult may easily be "shelled out" of its 

 cuticle and, if a male, the irregular arrangement of the abdominal 

 segments will be found fully developed, but entirely concealed by the 

 regular and symmetrical arrangement, characteristic of the females 

 and larvae. 



Description of the Imago. 

 Ramphocorixa balanodis^ n. gen. et sp. 



Colour. — Head yellowish, tegmina pale silvery grayish, almost irides- 

 cent in the female, darker in the male, the characteristic vermiculate or 

 banded markings usual in the group nearly obsolete. Pronotum grayish 

 or smoky brown, suffused with darker in the male. Rostrum pale yellow- 

 ish. Tergum, legs and whole ventral surface of female pure white. 

 Dorsum of male black, except the lateral margins, which are pale, the 

 ventral surface white, except for two broad almost black oblong bands on 

 either side, each nearly Yi the body-width in width, parallel to but not 

 quite reaching the lateral margin and extending over sternites 3, 4 and 5. 

 Genital segments pale in both sexes. A tiny reddish spot on the outer 

 surface of posterior coxœ, next the distal joint. The hairs of the limbs 

 tinged with yellow. Anterior and posterior margins of pronotum fuscous, 

 the former line sinuate. Surface of pronotum otherwise with three com- 

 plete pale brown lines, little, if at all, arched, and two shorter ones alter- 

 nating. Clavas nearly transpjirent, margined with brow.i, about one-third 



9 F. G. Smith, Quar. J. Mic. Sci,, 1909, pp. 54, 577 ; 1910, 55. 



