U Bulletin No. 159 



of curved bristles conspicuous, consisting of a stout basal 

 stalk at each side of the head, bearing about 36 bristles, 

 these flattened, strong, curved, expanded at their bases, the 

 inner edges with short, rigid, straight, obliquely-placed, or 

 erect setae, excepting a small portion of the tip of each. 

 Very minute soft hairs fringe the margin also, between the 

 rigid setse, and these soft hairs are present at the tips as 

 well as elsewhere. Antennae very slender and incon- 

 spicuous, erect, consisting of a long basal piece, then a 

 short, very slender one, ending with a very slender short 

 distal segment. Lower lip ( labium) black along the anterior 

 border; side margin a trifle excavated anteriorly, then sud- 

 denly arching outward, with four appressed marginal teeth 

 at the beginning of the arched portion. Anterior median 

 edge a little excavated, with, at each side, an outer rather 

 prominent acute tooth, a median tooth of about the same 

 size and character, and between the median and each outer 

 tooth three small teeth, making nine in all. Nearly parallel 

 with the lateral margin of each side are three hairs with 

 divided tips, the most anterior being opposite the appressed 

 teeth of the margin. Mandible of the usual structure in the 

 genus, consisting of a central elongate piece, arched without, 

 and bearing at the tip three rather strong acute black teeth, 

 the median of which is smallest; proximal to these teeth is a 

 series of three acute straight teeth successively shorter from 

 the outermost; then succeeds a series of six close-placed, 

 long, spine-like teeth, with two stouter ones completing the 

 series within. Two stout teeth, looking as if cut out of the 

 margin complete the armament, and are placed proximal to 

 all the others. The usual brushes of hairs arise from the 

 inner edge of the basal half of the mandible. The maxilla 

 consists of a stout broad basal piece from which arises a " 

 cylindrical segment tapering a little to the tip but blunt and 

 bearing at the extremity several short teeth. An inner lobe 

 about as broad as long bears on its side a tuft of hairs 

 extending beyond the tip; a triangular basal piece bears 

 several set^ along its anterior edge and at its apex is one 

 conspicuous pectinate spine. On each side of the head are 



