100 



HALTICIK/E. 



the Halticinje and the Eumolpo^e. The prosternum itself is 

 always more or less broad, except in one or two cases, for 

 instance, in the lndo-Malayan geims SphcerometojDa, where it is 

 almost concealed from view ; the apex of the prosternum, when 

 it is not rounded or truncate, sends off a thin piece towards 

 the epimeron, the inner projection of which it meets, thus 

 closing the front coxal cavity at its posterior edge (see fig. 52) ; 

 this character is very useful in grouping the genera. The 

 mesosternum in a large majority of Halticin^c is oblong, 

 triangular or quadrangular ; in some groups it is not visible at all, 

 the pro- and metasterna meeting each other. The position of the 

 hind edge of the prosternum relative to the mesosternum is of 

 taxonomic value. The epipleura of the elytra are generally broad 

 at the base, narrowing towards the apex ; in many cases they are 

 not continued to the apex, but terminate some distance before it; 

 sometimes they are as broad at the base as towards the apex, while 

 in the genus Hyphasis they attain a relatively enormous breadth 

 (see fig. 58). In correlation with the leaping habit the structure 

 of the legs has undergone suitable modifications. The hind femora 

 are thickened and very often channelled underneath for the 

 reception of the tibiae when in repose ; the latter are often short, 

 since long tibiae are unsuitable for jumping. In some Galerucijs^ 

 there is a distinct thickening of the hind femora, but the 

 corresponding tibia? are long and slender. The tibia? are similarly 

 channelled on the underside, and in many cases are provided 

 with a spur or spine at the apex (see figs. 48, 59) ; sometimes they 

 are broadened and more or Jess flattened towards the apex, with a 

 row of spines on each side. Each tarsus is apparently composed of 

 four segments, the basal one more or less triangular, the second 

 less so, the third broad and bilobed, the fourth or claw-bearing 

 segment long and slender, projecting much beyond the bilobed 

 segment. But these parts are sometimes greatly modified, e. g. 

 the first segment may be more than half the length of the tibia, 

 as in Longitarsus ; the second segment is always shorter than the 

 first, while the third segment, even when modified, retains to a 

 certain extent its bilobed form. The usual felt covering on the 

 underside of the tarsi also undergoes corresponding modifications. 

 In some genera, popularly called "bladder-clawed Halticines," the 

 claw-segment is swollen at the apex (see fig. 59), The point of 

 articulation of the tarsus with the tibia is generally at the apex 

 of the latter, but sometimes it is far away from the apex, as in the 

 genus Psylliodes. It will be noticed that all these modifications 

 are in keeping with the type of mechanism, leverage, etc., 

 necessary for the act of jumping. The claws are strong, prominent 

 and very often have a little projection on the underside (such 

 claws are called appeudiculate) ; sometimes they are bifid, and 

 rarely simple; in the case of the "bladder-clawed Halticines" 

 just mentioned, the claws are invisible when the tarsus is viewed 

 from above. 



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