92 Bulletin of the Brooklyn Entomological Society Vol. XVI 



segment large, much longer than second, about as long as seventh. 

 Connexivum very broad, only slightly reflexed, continuous ante- 

 riorly with the distinctly margined sides of thorax, which extend 

 to eyes. Form broadly oval. Genital segments prominent. 

 Length about 1.2 mm. 



The interpretation of the thoracic structure given above was 

 arrived at by careful comparison with the adult anatomy, and I 

 think it is correct ; but the matter will bear further investigation 

 and the attention of students is invited to it. 



Table of Apterous Forms. 



This key includes all the species recorded from the eastern part 

 of North America, excepting marginata Uhler and robusta Uhler, 

 which were described from the West Indies and may not in reality 

 occur on the continent ; moreover, I believe that their wingless 

 forms have not been made known. The color characters given 

 are general, not detailed, and pertain chiefly to the dorsal aspect. 

 The first form noticed in the key is not strictly apterous, as it 

 possesses very minute vestigial wings, but it is included here since 

 the species appears also in the fully winged condition. 



1. Pronotum largely developed, strongly arcuate and produced 



posteriorly, reaching base of second abdominal segment ; 

 minute white wing-pads present, projecting from under 

 pronotum at lateral angles ; first abdominal segment visible 

 only at sides ; color velvety brown, pronotum anteriorly 

 with a transverse yellow mark, connexivum dull yellow 



exteriorly; length about 1.7 mm atrata Torre-IJueno. 



Pronotum reduced, not much produced posteriorly, reaching at 

 most to base of first abdominal segment; wings entirely 

 absent; first abdominal segment fully exposed 2. 



2. Mesonotum concealed by pronotum ; metanotal triangles almost 



obtuse, extending inwardly much less than one-third the 

 width of the body at their level (fig. 3) ; entire thorax on 

 median line less than twice as long as first abdominal seg- 

 ment ; body strongly pilose ; color dark brown, the anterior 

 portion of pronotum, first abdominal segment, and con- 

 nexivum variably pale ; abdomen marked at base and apex 

 with patches of fine bluish gray pubescence, variably con- 

 spicuous ; length about 2.3 mm. . . .fontinalis Torre-Bueno. 

 Mesonotum visible; metanotal triangles very acute, longer (cf. 



