280 Mr. A. E. Eaton on 



all of them covered with pubescence. The tri-articu- 

 late labial palpi* are covered with a long pubescence, 

 excepting at their joinings. Their flattened, robust, 

 basal joints are as long as the other two together, 

 or nearly so; and their acute apical joints are equal 

 in length to about one-half of the second joints. The 

 maxillce are slightly curved and compressed, tooth- 

 less and acute, and somewhat hispid along their con- 

 cave inner edges. The maxillary palpus arises from a 

 slight depression in the middle of the exterior surface 

 of the maxilla, to which it is equal in length. The first 

 of its four joints is very short, the second is as long as, 

 but rather broader than, the fourth, and is slightly longer 

 than the third joint. The fourth joint is hirsute at the 

 tip, but the palpus is otherwise only sparingly pubescent. 

 Externally the somewhat triquetrous mandibles are cili- 

 ate. The internal prominent process of each is slightly 

 bevelled, and finely denticulate along its anterior edge 

 towards its pointed apex, and is furnished with a small 

 tubercle near the middle of its inner longitudinal edge. 

 The outer tip of the mandible ends in two stout prorect 

 spines, and a more slender obliquely curved spine : the 

 remaining part of the anterior edge is erose. The trans- 

 verse lahrum is ciliate, and slightly retuse. The 

 bilamellar tongue consists of an emarginate thickened 

 glabrous upper portion, bent upon an inferior bipartite 

 ciliate plate, whose divisions are obovate and remote. 

 At the joinings of the otherwise naked antennce are ver- 

 ticils of scanty spreading hairs ; the second joints of 

 these organs are three times as long as the first. 



The prothorax is transverse, as broad as the head, but 

 rather narrower than the mesothorax. In the typical 

 species the pubescent legs have compressed femora, and 

 the oblique tips of the tibiae are produced each into a 

 short spine ; C. halterata differs from the type in having 

 uncompressed femora, and ciliate tibii© and tarsi. 



The first six and the last two abdominal segments are 

 short — about one-third shorter than the remaining ones ; 

 the sides of the segments intervening between the first and 

 the last two, are flattened out, and their postero-lateral 

 angles are considerably produced, and ciliate ; the last 

 three abdominal joinings are clothed with stiff" erect 

 hairs. The arrangement and condition of the branchial 

 plates is very peculiar. The first pair arise from the 



* Prof. Westwood regards these as a second pair of maxilla?, aud 

 maxillary palpi. 



