THE AUCHEN0ERHYNCH0U8 HOMOPTERA. 337 



they are only able to turn to and fro on an axis from the outer to 



the inner angles of the cotyla. The trochantins are well 

 developed, louij; and moderately slender. A meracanthus is 

 strongly developed in some forms, feeble or wanting in others. 

 The trochanters are supporting, but however the articulations 

 are, between them and the femora, almost perpendicular to the 

 longitudinal axis of the latter, and present very strongly developed 

 see-saw movements ; the trochanters, moreover, are not broader 

 than the femora, which are moderately slender and of normal 

 appearance. 



2. CcrcopidcB. — The metasternum always has a considerable, 

 sometimes {PlnUenus) a very considerable, breadth (perhaps, one 

 should say, a greater length, as the extension which shall be 

 indicated is in the longitudinal dimension of the insect) ; along 

 the middle line one finds a strip, which widens anteriorly behind 

 the mesosternum to a plate, which is strongly chitinised, and on 

 eacb side of this solid middle strip one finds a very considerable 

 membranous part, which extends along the anterior margin of the 

 posterior coxae almost to their exterior angles, and proceeds 

 thence more or less forward, and towards the lateral margin of 

 the insect. The posterior coxce do not possess apparently broader 

 articulation than the intermediate coxce, and as regards this are 

 similar to the Stridulantia ; but the attachments are — as the 

 parts along almost the entire anterior margin of the coxse are 

 membranous— of another quality, and the true, more substantial 

 articulation between the coxtie and thorax is found therefore along 

 the peculiarly formed exterior inaryin of the coxa3, and at its 

 lower interior angles situated at the base of the abdomen. The 

 movements are ivell developed, see-saw-like, as in Stridulantia. The 

 interior margins of the two coxre are contiguous along the middle 

 line ; their free part extends backwards over the base of the 

 abdomen, and is proportionately longer than in the preceding 

 and following families. There is no meracanthus. The tro- 

 chanters have a somewhat varying form, and are somewhat 

 broader than the basal part of the femora (f. 5 b) ; the articula- 

 tion between the trochanter and femur is not very oblique, and 

 the segmental membrane is rather broad at the side facing the 

 middle plane ; so that the movements are more extensive than in 

 the Stridulantia and Jassidie. The femora are a little thinner at 

 their base than a little way from it, and on the side facing the 

 abdomen is found, a little from its base, a yood-sized oblique pro- 

 tuberance (f. 5 d), the signiticance of which I do not comprehend ; 

 but as it occurs in all the Cercopidce I have examined (even in 

 Macharota), and not in any other Auchenorrhyncha known to me, 

 it is probably a reliable family character. The protuberance 

 and its environs have a peculiai- scaly-like sculpturing ; its 

 interior is tilled with a mass looking like connective tissue. 



(To be continued.) 



