200 R. E. SNODGRASS. 



There are two apical lobes on each side born by the distal end of 

 the pleurum. The first or upper (fig. 50, A) is large and conspicu- 

 ous, wide at the base, convex externally, tapering distally, and curv- 

 ing posteriorly, ventrally and inward (fig. 60). The second (fig. 50, 

 B) is situated ventrad of the other and also mesad of it so that it is 

 almost hidden by the upper in a lateral view (fig. 60). This append- 

 age is shorter and thicker than the other. On the outer side of its 

 base is a small lobe that bears two slender hook like processes ( fig. 

 50, C). 



The guard of the penis projects posteriorly and upward from 'the 

 floor of the genital chamber. It is a simple elongate process deeply 

 cleft lengthwise above. From its base there arises a pair of long 

 curved hook like processes projecting upward at its sides. 



The central vesicle is imbedded in a dense mass of muscle and 

 connective tissue on the roof of the genital chamber The penis is 

 very slender, in its terminal part so slender as to be almost thread- 

 like. 



Pachyrrhina lugens Loew (PI. XI, figs. 51, 54). 



The abdomen is club shaped, being evenly widened toward the 

 posterior end. The eighth sternum is enlarged and prolonged be- 

 neath the hypopygium. 



The tergum of the hypopygium is convex dorsally, notched mesi- 

 ally on the posterior margin, produced into a small point on each 

 side of the notch. The sternum is very large; mesially it is deeply 

 cleft by a linear notch from the posterior margin. The pleurum is 

 well developed and is separated along its entire length from the ter- 

 gum. The suture separating it from the sternum is distinct along 

 the posterior two thirds of the segment, but vanishes in front of 

 this (fig. 51). 



The apical lobes (fig 54) are two in number on each side. The 

 upper (A) is elongate, fusiform and flattened They project from 

 the hypopygium like cerci from the tenth segment of other insects. 

 The lower appendage (B) is wide, flattened, scale-like, hooked ante- 

 riorly, and is curved forward so as to lie beneath the ninth tergum. 

 Two small lobes arise from the outer side of its base (C). 



The guard of the penis is a simple, grooved, decurved process. 

 From each side of its base there arises a small, flat, lobe with a ter- 

 minal hook. These and also the similarly situated processes in P. 

 polymera are probably the second gonapophyses. 



