118 THE ENTOMOLOGIST. 



simple short spike ; and one generally finds close to the apex 

 two more or less short {Triecpliora and Philcenus) or long 

 [Monecphora) thorns, which I have not been able to find in 

 V Aphrophora alni, in which I found, however, two big pits (f. 3 s), 

 one on each side of the segment, resembling the fastening-place 

 of the thorns, but of whose nature, however, I cannot say any- 

 thing. 



The flagellum has an absolutely different structui^e in the 

 nymph stages from what obtains in the imagines. In Philcenus 

 spiimarius, Linn., it consists of seven segments (pi. i. f. 4), which, 

 with the excej)tion of the shorter penultimate segment, are nearly 

 subequal in length ; the first is very stout, the others tapering 

 towards the apex. The first segment bears a number of small 

 normal sensory organs ; similar ones are found also, but singly, 

 scattered about on the 2nd-5th segments. The antenna of the 

 adult is also clearly discernible within that of the nymph ; the 

 thick basal segment of the flagellum of the former occupies about 

 half of the capacity of the same segment of the nymph, while the 

 filiform part of the flagellum of the imago extends throughout 

 the far thicker nymphal segment up. to the apex. 



3. Jassidce. 



Of this mighty family I have examined microscopically the 



antennae oi^Tettigonia ferruginea, F., and obtusa, F .pidiocerus 



ypopuli, L., msdePTyphlocyba roses, h.y Acocephalus striatus, F., 



6 Paropia scanica, Fsill.^Ledra aurita, L. (imagines and nymphs), 



V^Ulopa reticulata, F .^ JEthalioii reticulatum/L., Centrotus cornutus, 



h.YMembracis tectigera, Oliv., that is to say, representatives of 



most of the principal forms. I have examined with a strong 



lens all the other notable genera known to me. 



The antennae are placed in more or less distinct pits, which 

 in some foi'ms {Tettigonia, &c.) are situated before the eyes ; but 

 in oi\\QrB-^{Idiocerusl ALthalion, &c.) are placed under the eyes 

 very much as in many Fulgoridse. While they differ very greatly 

 in the various genera, they possess nevertheless a certain family 

 likeness which distinguishes them from the other families (pi. i. 

 f. 5-10). The second peduncular segment is, as a rule, subequal 

 to, or a trifle less than, the first in size. It is often peculiarly 

 sculptured in a scaly-like manner, but is always ivithout sensory 

 organs ; its apex never presents such a peculiar cup as that of 

 the Cercopidse. The flagellum is always clearly nmltisegmentate, 

 in the first half oL its length at^ least ; it is sometimes short and 

 very thiciy(C/Z6ipa, Centrotusy^thalion) , sometimes long, or very 

 long {Tettigonia, &c.), and very thin in the greatest part of its 

 length ; but its oval^ always somewhat — sometimes greatly — 

 thickened basal part MJJlopa) has numerous transverse furroivs 

 Cor at least tends towards this owing to coalescence of some of 



