106 BRITISH CICADA. 



with a spot at their base, and each of the femora has 

 a brown patch upon it. The female is more bronzy 

 and shining. 



Mr. Edwards records it "not uncommon near 

 Norwich in mixed hedges and amongst brambles." 



As specimens occur without the tibial dashes, it may 

 be doubted whether P. tibialis be a distinct species. 



This insect occurs also on poplars in June and 

 August, and Dr. Capron also has taken it at Shiere. 



Expanse, 0*36 inch, or 9-12 millimetres. 



Genus XXIIL— IDIOCERUS, Lciois. 



Head with the eyes broader than the pronotum. 

 Ocelli, when visible, facial; with afrontal suture running 

 between them. Antennae of the males — except in 

 I. distinguendus, I. tremulce, I. vitnmis, and I. aundentiis 

 — clavate, and inserted in a shallow cavity. Frons 

 rounded in front. Elytron membranous, with a limbus 

 or border overlapping the apex. Scutellum trigonate, 

 generally marked by two conspicuous, triangular, dark 

 basal marks ; which, with two black dots and a lower 

 deep horizontal groove, very fancifully represent a 

 " death's head." This singular representation also 

 may be seen in our Great Sphinx-moth, Acherontia 

 atwpos. Elytra longer than the body, and reticulated 

 into oblong cells, the costa in some males being 

 thickened and striated as in I. adustus. The elytral 

 nervures are often lost in the substance of the mem- 

 brane. Legs rather short ; the hind tibiae sometimes 

 have a coronet of short spines, and an extra row of 

 fine setse. Pulvilli bilobed. 



J. Curtis, in his 'British Entomology,' names six 

 indigenous species ; but later writers have described 

 seventeen or more species. Most of these I have 

 figured in the plates of this Monograph ; but it may be 

 anticipated that ultimately some of these may prove to 

 be varieties only. This seems to be the more hkely. 



