THE GENUS PISSODES. 



25 



the hairs on both the maxillae and labium, as shown in figure 6, is 

 characteristic and quite constant. The clypeus (fig. 5) is broad at 

 base, the sides narrowed to the apical angles, and slightly to dis- 

 tinctly longer than the labrum. The labrum (fig. 5) is more chitinous, 

 about three times as broad as long from apex of clypeus, the ventral 

 posterior margin angular, and extending beyond the margin of the 

 clypeus. The labral hooks are distinct (in balsam mounts), only 

 slightly longer than the labrum, and, as usual, support the anterior 

 portion of the epipharynx. An examination of the larvae of 14 

 species showed that there is considerable specific variation in the 

 form and proportion of the frontal area, clypeus, labrum, and man- 

 dibles. The last have characters of some divisional and subdivi- 

 sional value, but the characters have not been 

 sufficiently studied to present them in tabular 

 form for the identification of the species. 

 Certain characters common to one or more 

 species of a division are given in a provisional 

 synopsis on page 39. 



THE PUPA. 



(Plate V,B.) 



An examination of the pupae of 6 species 

 of the first division and 3 species of the second 

 division sJiows that the following characters 

 are common to all : The apex of the posterior 

 tarsus is even with the apex of the wing pad; 

 the apex of the antenna extends toward the 

 middle and in front of the anterior femur, 

 but does not rest against it or touch the wing 

 pad; the anterior, middle, and posterior femora 

 have each 2 minute subapical spines; the head 

 has 2^ prominent spines toward the vertex, 2 

 smaller ones on the sides toward the eyes 

 each side of the front between the eyes, and usually 3 pairs of 

 smaller ones on the beak between the frontal ones and the base of 

 the antennae; the pro thorax has 3 [jairs of dorsal spines, one pair 

 moderately closely placed on or toward the anterior margin, one 

 widely separated pair on the median area, and the other pair situ- 

 ated toward the base and still more widely separated; the lateral 

 area has 2 closely placed spines near the middle, and the basal 

 angle has an oblique row of 3 spines; the mesoscutum and 

 metascutum have each 2 rather closely placed spines on each side 

 of the median space; the abdomen has 8 distinct dorsal tergites, and 

 the dorsal area of each is armed with 2 spines, which slightly increase 

 in prominence from the first segment to the sixth or seventh. In 



Occiput - - - 



Fig. 7 .—Pissodes sitchensis : Head 

 of larva, lateral aspect. 6, 

 Frontal suture; c, subdorsal 

 stripe; o, submental lobe; p 

 lateral stripe. (Original.) 



, and 2 small ones 



