278 MR. B. F. CUMMINGS ON LICE 



one on each side, Postantennal area as broad as the base of the 

 preantennal semicircle. Temples rounded. Occipital margin 

 broad ; the two dorsal rafters of the skull are parallel and 

 widely separated. There are also two ventral rafters pursuing 

 the same course. At the occiput the dorsal and the ventral 

 rafter of each side are united one to the other by a concave 

 broad band forming the sides of the occipital hole. Forwards 

 the doi'sal rafters become evanescent in the chitin of the roof, 

 just about the level of the mandibles. Each ventral rafter in 

 front splits into two branches, the outer curling around into the 

 posterior part of the antennary socket and the inner one appa- 

 rently becoming absorbed in the thick chitin, which gives the 

 mandibles articulation. Antenna: First segment large, swollen, 

 all three segments about equal in length. Hair- canal absent or, 

 at any rate, very shallow ; two somewhat convergent chitinous 

 bands run from the clypeus to the front margin of the head and 

 indicate the sides of the canal. As in T. climax and others 

 the frontal marginal band is thickened, with a narrow, median, 

 longitudinal, white cleft. In a greatly developed hair-canal, 

 such as T. subrostraius N. possesses, there is no band crossing 

 the frontal sinus, the lateral mai-ginal bands, one on each side, 

 running down the sides of the hair-canal. Thorax : Narrower 

 than the head. There are two distinct parts — pro-|-mesothorax 

 and metathora.x or prothorax and meso-fmetathorax. The latter 

 is a little tlie broader. Lateral margins of both are rounded. 

 Ooxaj of first pair of legs lie close to one another in the centre. 

 First pair of legs short, the tibipe of the second and third pairs 

 remarkably long. Abdovie')i : Tapers elegantly to the anal 

 extremity. The tip is bifid. The material at my disposal is 

 insufficient to determine the precise morpliology of the bifid 

 tip. In Damalinia, according to Mjoberg, it is the produced 

 sternite of the last segment. There are two other species of 

 Ti^ichodectes with bifid tips to the abdomen, viz., T.forficula P. 

 and T. appendicidatus P., but I have not been able to examine 

 either of these for comparison. A tergite on each of the first 

 three segments ; but each tergite gives a suggestion of being 

 double, and in the following three segments each tergite is 

 plainly divided in half by a transverse light-coloured band. 

 It is possible that these divisions are only colour-differences. 

 On the penultimate segment, a small tergite. The termination 

 of the abdomen is of a clear whitish chitin. A single sternite in 

 each segment. Each sternite, even in the posterior segment, is 

 an integral whole, so that a genital plate may be said to be 

 absent, although the last two sternites are, on each side, 

 bracketed together by a lateral band of brown chitin. 



External Form. Female (text- fig. 14). — The usual sexual 

 differences in the antennae. Abdomen : Ovate. A single tergite 

 and sternite on each segment, dark brown in colour. Tergite 1 

 fits the whole space between the pleurites. In the tergites that 

 follow, there is a clear space laterally between tergite and 



