198 DE. C. CHILTON ON THE SUBTEREANEAN 



three bear at. the extremity one or two small " olfactory cylinders" of the usual shape 

 in addition to a few simple setse. 



The lower antennoi (fig. 2) are about three-fourths as long as the body, the flagellum 

 being much longer than the peduncle. The first two joints are subequal, short, as broad 

 as long, without setse ; the third is as long as the first and second together, its upper margin 

 slightly convex, lower margin straight, one or two small setae on the lower margin at 

 the distal end ; the fourth is about half as long again as the third, but slightly narrower, 

 sides straight and parallel, one or two small setie on the margins, and tufts of longer 

 setae above and below at the extremity ; the fifth joint is similar to the fourth but about 

 twice as long, each margin bears about four small setse and there are tufts of longer 

 setse at the end ; the first joint of the flagellum is about twice as long as the second, 

 which is about as broad as long ; the remaining joints (about 35 altogether) gradually 

 become longer and narrower till at the end each is about six times as long as broad, 

 each bears one or two small setae at the distal end, but toward the extremity of the 

 flagellum these become very small. 



The upper lip does not difl'er in any important respect from that of P. assimilis. 



The mandibles (fig. 3) also appear to resemble those of P. assimilis, but the left 

 mandible has only three teeth on the terminal cutting-edge, with three also on the 

 secondary cutting-edge. In the specimen from which I have taken the drawing (fig. 3), 

 these teeth are much sharper and more acute than those showTi in the figure of P. as- 

 similis (PI. XVI. fig. 6), but this is probably due to the fact that they belong to a 

 younger specimen. In the figure they are flattened out so as to be seen full in front, 

 while those of P. assimilis are seen in profile. 



The lower lip (PI. XVIII. fig. 4) differs considerably in shape from that of P. assimilis. 

 Each lobe is triangular, inner margin straight, outer margin very convex, especially 

 toward the base, the extremity being more or less acute, not rounded, and there is a 

 small projection on the inner margin at some little distance fi*om the extremity. The 

 extremity is densely covered with long setae ; the inner margins and the distal portions 

 of the outer margins are fringed with fine setae. 



The first maxilla (fig. 5) bears a general resemblance to that of P. assimilis, but 

 the inner lobe is much broader, especially toward the extremity, which is rounded and 

 bears about 9 or 10 long plumose setiB, about twice as many as in P. assimilis. The two 

 simple setfB also present at the extremity are situated near the base of the third and 

 fourth setae respectively from the outer margin of the lobe. In P. assimilis they are 

 situated at the base of the two inner setae. 



The second maxillcB (fig. 6) differ from those of P. assimilis in the following points : — 

 The inner margin of the basal portion is more convex, and bears a very distinct row of 

 long plumose setae, which have thickened bases ; those at the distal end have the base 

 quite short, but toward the proximal end of the row the bases become gradually longer. 

 At the lower end of the row on the surface of the base is another somewhat imperfect 

 row of simple setae. The inner (fixed) lobe is longer than in P. assimilis and has the end 

 more rounded, and the long plumose setse, instead of being confined to the extremity, 

 extend for some distance along the inner margin toward the base. 



