Mr. C. G. Lamb on Exotic Chloropidee. . 37 



line, and this form agrees quite well witli the description of 

 frontalis. The species with the more approximate veins is a 

 little smaller and its vertical " triangle " is more shining ; 

 the raised central line tends to be multiple — in fact, it agrees 

 very closely indeed Avith Speiser^s description of frontellinvs 

 (Kilimandjaro Meru Exp.. Diptera, x, p. 198). In the Bur. 

 Coll. are specimens still more robust than the fiist species, 

 with venation as in fig. 1 and with rather more glassy wings, 

 but otherw^ise practically identical with the first series. 



It appears best to consider the first and last sets of speci- 

 mens as belonging io frontalis, and the other to frontellinus ; 

 in none of the published descriptions is any figure of the 

 venation given. 



P. frontalis. The large form : Bur. Coll., Durban (L.Bevis). 



The smaller form : Cam. Coll., Durban (F. M.^. 

 P. frontellinus. Cam. Coll., Durban {F. M.). 



Three species in the collection belong to the smaller 

 section of the genus with a pale vertical triangle. Hitherto 

 there are described but two species in this section (Becker, 

 II., p. 388). Neither of these species accords with the 

 specimens in the collection, and hence they must be con- 

 sidered new. 



Pachylophus lituraticrus, sp. n. 



This species belongs to Becker's section with pale legs 

 and triangle (II. p. 387). 



Head (top view) : — Vertex nearly as broad as twice the 

 visible eye-breadth, somewhat transversely concave on the 

 front, bright dullish yellow ; the triangle is shining orange 

 without furrows &c., extending not quite to the frons, with 

 a rounded darkened tip, very slightly concave sides, and with 

 the vertical base just less than the eye-distance; the ocellar 

 spot black. In profile the angle between the vertical and 

 facial tangent-planes is a little less than 90°, the frons being 

 just visibly prominent. The pale yellow cheeks are about | 

 the depth of the 3rd joint ; the latter is quite normal, yellow 

 except for the part below aristal insertion; the latter is 

 black and of usual form. Palpi yellow. Hind head orange ; 

 a darkening behind the ocellar spot, and a pale spot each 

 side just at the top angle of the eye, on which the tiny 

 vertical bristles stand. 



Thorax : dorsum elegantly striped ; along the middle 

 is a broad stripe of reddish brown bordered by pale narrow 



