118 THE ENTOMOLOGIST. 



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

 two more or less short {Triecphora and Philanus) or long 

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

 Aphrophor-a 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 structure in the 

 nymph stages from what obtains in the imagines. In Philceniis 

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

 with the exception 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 of Tettigonia ferruginea, F., and obtusa, F., Idiocerus 

 populi, L., male ; Typhlocyha rosa, L., Acocephalus striatus, F., 

 Paropia scanica, Fall., Ledra aiirita, L. (imagines and nymphs), 

 Ulopa reticulata, F., JEthalion reticidatum, L., Centr'otus cornutus, 

 L., Memhracis 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 forms {Tettigonia, &c.) are situated before the eyes ; but 

 in others {Idiocerus, Mthalion, &c.) are placed under the eyes 

 very much as in many Fulgoridae. 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 Cercopidae. The flagellum is always clearly multisegmentate, 

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

 very thick {Ulopa, Centrotus, JEthalion), 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 {Ulopa) has numerous transverse furrows 

 (or at least tends towards this owing to coalescence of some of 



