10 OLAVICORXIA. [SilphidcR. 



anterior C'OXSD, wliich are conical and contiguous, and finely granulated 

 eyes which are sometimes wanting; the maxillae are Lilobed ; the antennae 

 are straight, inserted before the eyes, and thickened, or more often 

 furnished with a club; the thorax is margined; the pro thorax has the 

 epimera and epistcrna not distinct ; the mesosternum is short, and its 

 epimera reach the coxae ; the metasternum is large ; the abdomen has, as 

 a rule, six free segments ; in Sphairites only it has five ; the legs are 

 variable, sometimes stout, sometimes slender ; as a rule the tibiae are dis- 

 tinctly spined externally ; the tarsi also vary as regards the number of 

 their joints. 



The family may be divided into the following tribes: there is, however, 

 a very great difference in the views of authors regarding the division : 

 Spheerites, for instance, is regarded by some as merely a genus of the 

 Silphina, by others as a tribe of the Silphidae, and by others as a separate 

 family Spha?ritidae. 



I. Anterior coxal cavities closed behind. 



i. Posterior coxae laminate ; size very minute ; tarsi all 4-jointed 



in both sexes CLAMBIXA. 



ii. Posterior coxae simple ; tarsi variable, but never all 4-joiuted in 



both sexes. 



1. Upper surface, as a rule, glabrous or almost glabrous, shining ; 

 episterna of mesothorax small and linear, of metathorax 



hidden ANISOTOMINA. 



&. Upper surface pubescent, dull ; episterna of meso^horax rather 



large, subguadrate, of metathorax free CHOLEVINA. 



II. Anterior coxal cavities open behind. 



i. Abdomen with five free ventral segments SPH^RITINA. 



ii. Abdomen with six free ventral segments SILPHINA. 



CLAMBINA. 



This tribe has by many authors been placed in close proximity to the 

 Trichopterygidse, and it does in fact bear a close relationship to that 

 family, from the fact that the edge of the wings is fringed with long 

 hairs ; in other points, however, especially in the fact that in most 

 species the body is retractile and capable of being rolled up into a ball, 

 the tribe is closely related to Agathidium ; the head is large and 

 transverse, and the antennae 11-jointed, 10-jointed, or 9-jointed, with 

 2-jointed club ; the anterior coxae are conical and contiguous 'with the 

 cavities closed behind, and the middle coxae in our two British genera 

 are slightly separated ; all the tarsi are 4-jointed ; the species are all very 

 minute, of convex and short oval form, and are found in decomposing 

 vegetable matter. 



There are two British genera which may be separated as follows : 



I. Antennas 10-jointed, with club 2-jointed, inserted at a 



distance from eyes ; abdomen with six segments . . . CALTPTOMEEUS, Sedt. 



II. Antenna? 9-jointed, with club 2-jointed, inserted near 



eyes ; abdomen with five segments CI/AMBUS, Fisct. 



