HYPHASOMA. 



157 



developed, frontal elevations also well developed; mouth-parts 

 prominent, well developed ; sometimes the surface of the head 

 immediately behind the clypeus is concave. Antennae usually 

 slender, moderately long, reaching to between the middle and 

 about three-fourths of the length of the elytra; first segment 

 always the longest, second generally the shortest, third usually 

 longer than second; often the third and fourth are equal, but 

 their relative lengths vary ; the following segments are more or 

 less nearly equal to each other, with the apical segments, viz. 

 eighth to tenth, tending to become smaller; last segment always 

 bluntly pointed ; very rarely the apical segments are very slightly 

 thicker than the basal; the antennae are generally covered 

 with fine hairs, but always less so on the three basal segments. 

 Prothorax always much broader than long, with sides generally 

 rounded; anterior and posterior lateral angles each bearing a 

 fine seta which arises from a pore ; at this point the surface is 

 somewhat thickened, more so at the anterior angles than at the 

 posterior; upper surface somewhat convex, sometimes distinctly 

 punctate, while sometimes the punctures are so fine that they 

 are not clearly visible unless a high power is used in a suitable 

 light; the lateral margins are often somewhat explanate with 

 edges reflexed, but this condition is less pronounced than in the 

 genus Hyphasis. Scutellum always triangular, varying in dimen- 

 sions ; surface always impunctate. Elytra usually broader at the 

 base than the prothorax, although they broaden behind ; humerus 

 rounded, not prominent and without any longitudinal impression 

 on its inner side : surface always confusedly punctate, the 

 punctures being more conspicuous in some cases than in others, 

 and sometimes stronger on the basal part than on the apical; 

 lateral margins sometimes slightly explanate with edges reflexed ; 

 epipleura not so broad as in Hyphasis, and often concave. 

 Underside: presternum oblong or narrowly oblong, with the 

 apex truncate and the surface flat or longitudinally concave ; 

 tibiae channelled on their dorsal side, those of the posterior pair 

 with apex emarginate and armed with an acute spine, the others 

 without a spine at the apex ; posterior tarsi with the first 

 segment equal to or greater than the next two together, claw- 

 segment always inflated or dilated ; claws appendiculate ; posterior 

 femora strongly incrassate. 



Owing to the shape of the prothorax (which is strongly 

 transverse and somewhat depressed, with broadly explanate and 

 flattened margins) and the extraordinary breadth of the epipleura 

 of the elytra, Jacoby separated BypJiasoma from Hyphasis. 



In this genus it often happens that a species may have some 

 individuals very light in colour while others are much deeper; 

 this renders identification difficult when a single individual is 

 caught. I believe that several species have a, very wide distri- 

 bution, and their proper determination becomes a matter of great 

 difficulty. 



