NO. 13 STAPH YLINIDAE — BLACKWELDER I3 



outline, somewhat convex, and the facets are moderate in relative size. 

 The oculata is large, occupying nearly three-quarters of the area of 

 the eye, as already described. No ocular suture or independent ocular 

 sclerite has been observed, but there is a narrow unpigmented band 

 separating the faceted part from the vertex. Ocelli are not present. 



The vestiture of the head consists of a moderately dense clothing 

 of setae along the posterior margin dorsally, with a few very large 

 and long setae placed as follows: A pair at the anterior edge of the 

 vertex at the corners of the postclypeus ; one above the base of each 

 antenna; one near the middle of the inner edge of the eye; and one 

 to three in the area between the eye and the posterior constriction. 

 The posterior areas are continued around onto the lateral and some- 

 what onto the ventral surface. 



THE APPENDAGES OF THE HEAD 



The appendages of the head consist of a pan' of antennae, a pair 

 of mandibles, a pair of maxillae, a hypopharynx, and a labium. With 

 the exception of the antennae, which are sensory in function, these 

 are all concerned with ingestion of food and are known collectively 

 as the mouthparts or trophi. 



The antennae (fig. i D) are situated at the anterior edge of the 

 epicranium. They are inserted -into an opening or antenna! fossa 

 (fig. I A, af). They are 11 -segmented and feebly clavate, with the 

 first segment elongated, as long as the second and third together. 

 The segments diminish in length from the first to the fifth, and in- 

 crease in width from the sixth to the tenth. The seventh to eleventh 

 segments are covered completely with minute setae, and the eleventh 

 alone has these setae interspersed with groups of minute pores (fig. 

 I B). The outer joints (fig. i C) allow only a limited amount of 

 movement, whereas the basal ones permit a much wider latitude. All 

 the segments have a sparse vestiture of longer setae which are situated 

 rather at random. 



The mandibles (fig. 2F, J) are prominent, falciform jaws, heavily 

 sclerotized, and each articulated with the anterior margin of one side 

 of the head. The expanded proximal part is produced into a slender, 

 curved distal part which tapers to a blunt point. The lateral margin 

 of the latter is regularly continuous with the curved outer margin of 

 the basal part. The anteromesal corner of the basal part is produced 

 to form two small, bluntly acute teeth (mat). The notch separating 

 the two teeth of the left mandible (fig. 2 J) is nearly three times as 

 deep as the corresponding notch on the right mandible (fig. 2F). 



