314 JAMES WATERSTON. 



constant. At present it seems best to consider the Eastern and Western forms as 

 local races of one species. Besides the differences already noted there appear to 

 be others in the ratio of the autennal joints; e.g., the club of the antemia is 

 relatively longer in typical afer than in the var. The lighter coloration of the Aburi 

 examples may be due in part at least to preservation in alcohol. Through the 

 kindness of Professor Silvestri a cotype of A. afer has been presented to the 

 Imperial Bureau of Entomology, and a cotype of var. cavilabris has been deposited 

 at Portici. 



Genus Eusemion, Dahlb. 



Eusemion, Dahlbom, Oefv. Svensk. Vet.-Akad. Forh., xiv, 1857, p. 293. 



Although considered by Mayr to be equivalent to Cerapterocerus, Westvv., this 

 group probably deserves separate treatment. It is distinguished by the rather 

 broad sub-triangular wing, the large single cloud, and the neuration, the marginal 

 being rather long, and the postmarginal and radius, though short, both distinctly 

 developed. 



Eusemion cornigerum, Walk. 



Encyrtus comiger, Walk., Ent. Mag., 1838, p. 114. 



$. Blackish brown ; antennae, especially on the scape, with a slight cupreous 

 gleam ; eyes dark chocolate ; vertex and upper frons refringent, dark metallic 

 green. Thorax slightly darker than the abdomen, with at most a trace of metalhc 

 reflection (greenish) apically or marginally towards the apex. Wings with the 

 veins blackish brown, pattern as in fig 3, a, the cloud being darkest immediately 

 behind the costa between the postmarginal and the apex of the wing. Legs with 

 all the fifth tarsal joints, claws, and empodia darker ; remainder of the tarsi, 

 apices of tibiae (broadly) and the spurs pale, otherwise nearly as dark as the 

 abdomen and nowhere metallic. 



Head very much wider than deep across the lower face (17 : 14) ; eyes in profile 

 occupying four-sevenths of the depth. Vertex slightly broader than in E. pattersoni, 

 Waterst. (two-ninths the width of the head). Ocelh in an isosceles triangle so short 

 as to be almost equilateral ;' posterior pair nearer to one another than to the 

 anterior ocellus, and separated from the margin of the vertex by httle more than 

 their own length. Between the anterior ocellus and the edge of the frontal 

 flattening there are four rows of punctures, the middle pair containing 5-6 large 

 and conspicuous ones ; along the orbits the rows are obscure and consist of 

 smaller, less conspicuous punctures. Toruli oval, sub-reniform in shape, the 

 opposed edges being flatter and a little concave medianly. Clenal striae rather 

 coarse, 4 bristles above the genal edge. Between and above the toruli are 

 about 16 bristles. 



Mouth-parts. Labium distinctly concave, with 8 bristles. As the upper margin 

 of the chitinised area is also concave, the dissected labrum has the shape of a 

 bi-concave lens. Mandibles (7 : 5) tridentate (fig. 3, d). Maxillary palpus 15, 10, 

 10, 21 ; in same ratio the breadths are 5-J-, 7, 6, 9. There is a strong bristle 

 on the stipes well before the palpus and two shorter (median) on the mentum. 



