CLAVICORNIA. 129 



Wood, Putney, Tonbridge ; Kingsgate ; Glanvillcs Wootton ; Barnwood, near Glouces- 

 ter ; Birmingham district; Northumberland district, very rare; not recorded from 

 Scotland ; Ireland, near Dublin. 



PTILIINA. 



This tribe contains seven European genera, all of which, with tho 

 exception of Micridium, arc represented in Britain ; they are, as a rule, 

 much more easy to determine than the Trichopterygina. 



I. Thorax broadest at base ; pygidium covered. 



i. Metasternum not extending to the sides of the body . NOSSIDITJM, Er. 



ii. Metasternum reaching the sides of body .... EURYPIILIUM, Matfh, 



II. Thorax broadest before base. 



i. Thorax at base extending over the shoulders of the 



elytra at the sides, sinuate narrowly before base, so that 



the apical margin is broader than the actual basal 



margin ACTIDIUM, Matth. 



ii. Thorax fitted to the base of elytra. 



1. Metasternum extending to the sides of the body ; 

 thorax not, or only moderately sulcate. 



A. Pygidium exposed ; sculpture almost always 

 tuberculate * PTILIUM, Er. 



B. Pygidium covered ; sculpture variolose . . . PTENIDHTM, Er. 

 2 Metasternum not extending to the sides of body ; 



thorax very deeply sulcate . . . MiLLioinr, Mots. 



PTILIUIVI, Ericlison. 



. Nineteen species of this genus are enumerated by Mr. Matthews in 

 his monograph from Europe and America, but several have since been 

 described ; they are distinguished by having the thorax fitted to the base 

 of the elytra, the pygidium exposed, and also by the generally distinctly 

 tuberculate or asperate sculpture of the thorax, by which they may, as a 

 rule, be separated from the species of Actidium, which bear rather a 

 strong resemblance to them in general appearance ; the species are found 

 in moss, hot-beds, dead leaves, &c., or under bark. 



I. Thorax not or obsoletely channelled in middle. 



i. Thorax more or less quadrate, not constricted be- 

 hind. 



1. Thorax longer than head. 



A. Thorax dilated behind; sculpture of elytra 



finer P. MAEGINATUM, Auli. 



B. Thorax not dilated behind ; sculpture of elytra 



coarser P. KUNZEI, ILeer. 



2. Thorax shorter or almost shorter than head. 



A. Elytra scarcely broader than thorax ; sculp- 

 ture of thorax fine. 



a. Form broader ; antennae thicker .... P. BBEYICOLLE, Matth. 



b. Form narrower; antenna? more slender . . P. EUGULOSUM, All. 



* In Ptilium Halidaii, the head and thorax are foveolate-punctate. 

 VOL. III. K 



