34 MANDIBULATA. — COLEOPTERA. 



Sp. 1. crepitans. Plate II. f. 6. Ferrugineus; elytrls siibcostatis, 

 cyaneo-mrescentibus ; antennar'um articulo tertio quartoque ab- 

 domineque obscu7-is. (Long. c. 2| — 4^ lin.) 



Ca. crepitans, Linne. — Br. crepitans. — Steph. Catdl. No. 37. 



This remarkable insect varies much in size and in colour : the head is oblong, 

 ferruginous-red : the antennae are of the same colour, with a conspicuous ob- 

 scure spot on the third and fourth joints : the eyes are projecting and black; 

 the thorax is cordate, the colour of the head, shghtly wrinkled transversely, 

 and very obsoletely punctured with a longitudinal impressed Kne : the scu- 

 tellum is ferruginous : the elytra are much broader than the thorax, oblong, 

 rather oval, round at the base, very shghtly pubescent, and dehcately punc- 

 tate : they are strongly costate, or ribbed, and they vary much in the in- 

 tensity of their colour, in some species the green tinge predominates, in others 

 the blue, the smallest specimens being usually the brightest, — which is the 

 reverse of the continental specimens, as De Jean says the largest are the most 

 vivid green. — Beneath, the abdomen is of an obscure brown : the middle of 

 the breast is more or less reddish : and the legs are ferruginous-red. 



Far from an uncommon species, occurring even among the " busy 

 haunts of man," on the northern verge of the metropolis ; but its 

 most usual habitat appears to be on the banks of the larger rivers, 

 and near Gravesend and Southend, on the shores of the Thames, it 

 occurs in great profusion ; it also occurs near Cobham in Surry, at 

 Hertford, in the New Forest, Hants, near Teignmouth in Devon- 

 shire, and in Glamorganshire. 



I noticed in page 12, that the typical genus of this family was 

 endowed with a remarkable and singular property as a defence 

 against the attacks of its enemies, and as this species is not only the 

 most common of the genus in Britain, but also the one upon which 

 the observations were originally made, I shall here detail it. 



At the posterior extremity of the abdomen a little sac or bladder 

 is placed, which is furnished with the means of producing a liiglily 

 volatile fluid, which the animal has the power of suddenly ejecting : 

 this fluid is apparently of an acid nature, and is of so pungent a 

 quality as to irritate considerably any part of the body upon which 

 it falls ; and if any should by accident get into the eyes, the pain 

 for a time is excessive ; and if permitted to be discharged upon the 

 skin, it becomes coated with a kind of dusky tinge. Now from 

 the very rapid volatilization of this fluid Mdien emitted from the 

 body of the animal, a curious effect is produced, accompanied 

 with a considerable explosion — especially in the larger continental 

 species, as related by foreigners— and a bluish kind of vapour 



