NEW BRITISH SPECIES, ETC., IN 1863. 85 



banks, or under stones in the bed, of the river Irthing, at 

 Lanercost, Cumberland. 



At first sight it considerably resembles B. opacus, but 

 may be distinguished from that species by the following 

 characters : — It is smaller, and not so robust, the elytra 

 especially being shorter ; the antennse are rather more slen- 

 der, and lighter in colour ; the head is more shining, much 

 less deeply punctured, and with only a delicate transverse 

 line between the insertion of the antennae ; the clypeus, more- 

 over, is alutaceous, yet almost shining, whilst in B. opacus 

 it is rougldy coriaceous ; the thorax is more opaque, more 

 obsoletely punctured, and with a narrow, smooth, somewhat 

 shining, longitudinal middle space without any channel, 

 whereas in B. opacu.s there is a very delicate but distinct 

 dorsal gi-oove ; the sides of the thorax, moreover, are sub- 

 sinuate towards the base, with the hinder angles decidedly 

 prominent at their extreme points, and herein the two spe- 

 cies in question differ considerably, as the sides of the thoi'ax 

 in B. opacua a?'e obliquely truncated towards the base, with 

 the hinder angles very obtusely rounded. I would here 

 remark that the words '' ohtnsis, 7ion verb obtusissimis,'' 

 applied to the posterior angles of the thorax in B. erratkiis 

 by Erichson, hardly give a correct idea of their appearance, 

 since they are all but acute. 



In B. erraticua the elytra (which are red, sometimes 

 being darker near the scutellum and suture) exhibit a some- 

 what greasy appearance ; they are also shorter than in B. 

 ofiacm, and not so deeply or closely punctured. 



The head and thorax are inclined to pitchy brown, the ex- 

 treme apex of the abdomen being more or less rufous ; the 

 former parts are rufo-piceous in some foreign specimens sent 

 by Dr. Kraatz to the British Museum, in which also the red 

 apex to the abdomen is very conspicuous, but the species 



