OF WASHINGTON, VOLUME XVI, 1914 153 



From the posterior end of the front runs on each side a curved 

 translucent line to the outside of the antennal base, limiting a 

 large, triangular area which may be homologous to the so-called 

 adfront of Forbes; each of these areas contains two small setae 

 posteriorly. 



The epistoma 1 is well developed and bears two pairs of minute 

 setae. 



The epistoma is connected with the labrum by a large soft- 

 skinned part, the post-labrum of Lyonet, (the "clypeus" or "an- 

 teclypeus" of Packard, Sharp and others). 2 



The labrum (fig. 4) is large and well chitinized, bilobed, the 

 anterior edge rounded and slightly emarginate; on the upper side 

 it bears one central pair of strong setae and along the edge five 

 pairs of smaller setae. On the under side of labrum and slightly 

 projecting in front of it, is the fleshy epipharynx (fig. 5) armed 

 along the anterior margin with a series of spines and bearing on 

 each side a large tuft of long hairs. It also has a pair of sensory 

 pits, and two pairs of small, symmetrically arranged, elongate, 

 elliptical, chitinous plates, 3 the proximal ones with a little tooth. 

 The margin of the epipharynx is strengthened by lateral rod- 

 shaped sclerites. 



The antennae (fig. 11), are short, three-jointed; 4 the basal joint 

 is large, membranous, without spines. The second joint is well 

 developed and well chitinized. It bears two large spines and two 

 sensory processes. The third joint is much smaller and bears one 

 seta and two sensory processes, the larger one of which is slightly 

 chitinized around its base. 



The mandibles (fig. 10), are strong and placed horizontally. 

 They have three, large, pointed teeth, and a fourth, small rudi- 

 mentary tooth, indicated only on the ventral side. The large, 

 bluntly terminating cutting edge is separated from the teeth by 

 a small incision. The outer edge bears two strong seise, the api- 

 cal one of which is on the base of the fourth rudimentary tooth. 

 At the base of the cutting edge is a bunch of long branched hairs. 



1 Epistoma is the chitinized marginal area between the two processes 

 on which the fossse of the mandibles articulate. This part Forbes calls 

 "clypeus," (I.e. p. 96, footnote), on the supposition "that this name agrees 

 better with its homology in other orders." 



2 Forbes does not give it any name at all, and applies, as mentioned, the 

 term "clypeus" to the epistoma. 



3 Compare the similar structure in Coleopterous larva; mentioned by 

 Geo. H. Carpenter and Mabel C. MacDowell in, "TheMouthparts of Some 

 Beetle Larvae, WithEspecial Reference toTheMaxilluloe and Hypopharynx," 

 The Quarterly Journal of Microscopical Science, vol. 57, 1912, pp. 373-393, 

 figs. 10, 191, 24, and 25. 



4 We accept with reservations, Trscgaardh's interpretations, (in his val- 

 uable paper, Arkiv. for zoologi, vol. 8, 1913. Stockholm). Possibly his 

 first joint is but a basal membrane and the terminal sensory process a true 

 joint. 



