IV) 10] North American Paniscini 189 



THORAX. 



The thorax in general is strongly compressed laterally, 

 very finely pubescent, and is of a yellowish russet color. 



PROTHORAX. 



The prothorax, as seen from the side, is triangular in outline, 

 marked by fine, distinct, obhque, transverse striations which are 

 most noticeable near the lower anterior portion of the plate, while 

 viewed from above it is a very narrow transverse band. Its 

 anterior margin is straight and elevated, forming a flange, 

 which projects sHghtly forward. Looking down from above, 

 there can be easily detected with the aid of a microscope, a 

 semicircular indentation or groove, which leads to the query, 

 "Was this portion once a distinct plate representing a much 

 reduced pronotum while the large triangular plate at the sides 

 represented a much enlarged pro-pleuron?" It is set out very 

 prominently from the mesethoracic plates by quite conspicuous 

 sutures. The facial portion of the prothorax, lying just behind 

 the head (episternum?) is somewhat hoof-shaped having a 

 deeply impressed line extending from the point where the head 

 joins the prothorax to a point near the insertion of the fore 

 coxa, thus dividing it into right and left halves. 



MESOTHORAX, 



The mesonotum is a broad plate distinctly convex, lying 

 between the fore-wings and extending forward to the dorsal 

 portion of the prothorax. Starting near the anterior margin 

 and at equal distances from the middle of the plates, are two 

 lateral grooves known as the parapsidal furrows which curve 

 slightly inward and extend nearly to the scutellum. These 

 grooves become weak posteriorly, being only slightly noticeable 

 after they have passed the middle of the plate. The anterior 

 margin of this plate is bent slightly upward or reflexed, and this 

 is continued around the sides as far back as the tegula, where it 

 leaves the margin and becomes a distinct ridge which passes 

 obliquely backward across the plate. 



Directly behind the mesonotum already described, is the 

 scutellum, the median portion of which is trapezoidal in outline, 

 longer than broad, the longer base anterior, the shorter base 

 being posterior and slightly over half the length of the former. 

 Between the mesonotum and median portion of the scutellum 



