618 BRABEJUM B 



BRACHELYTRA (Cuvier ; MICROPTERA, Gra- 

 venhorst). A group or sub-section of beetles of con- 

 siderable extent, belonging to the section, having five 

 joints in all the tarsi (Pentamera), and corresponding 

 with the Linnaean genus Staphylinus. The insects 

 composing this sub-section are distinguished easily by 

 the shortness of the wing-covers, which, although they 

 entirely conceal the organs of flight, when folded up, 

 are yet seldom more than one-third of the length of 

 the abdomen, the remainder of which is consequently 

 exposed. The wings themselves are of a large size 

 (whence the impropriety of the name given to the 

 insects by Gravenhorst, signifying small wings) ; but 

 by means of numerous folds, and owing to their very 

 thin and delicate structure, they are easily shut up 

 and hidden beneath their two short covers. Unlike 

 the ground beetles, Carabida; (to which these insects 

 are related, according to Latreille), the lower jaws 

 are armed only with a single pair of palpi, or feelers ; 

 or, more strictly speaking, the terminal exterior portion 

 of these organs, instead of exhibiting the form of a 

 palpus, as it does in the latter insects a peculiarity 

 of organisation beautifully dependent upon corre- 

 spondent peculiarity of economy is either entirely 

 soldered to the organ of which it is a part, or appears 

 in the form of a dilated and inarticulate appendage ; 

 the antennae are short, and either of an equal thick- 

 ness throughout, or thickened at the tips, and com- 

 posed of moniliform, or cup-shaped joints. 



By Linnaeus these insects are arranged at the end 

 of the Cokoptera, and by some authors they have 

 been considered as forming a passage to the next 

 order, the Orth&ptera, at the head of which the ear- 

 wig (Forficula) is placed. It is not to be denied that 

 there is great similarity in appearance between some 

 of the moderate-sized species of this sub-section of 

 the earwigs, especially in the shortness of the wing- 

 covers and the exposed abdomen, as well as in the 

 terminal appendages of the body, which, although 

 they are of a large and forceps-like construction in 

 the ear-wig, are evidently represented by the pilose 

 setae which the brachelytra possess at the same part 

 of the body. In their habits there is likewise con- 

 siderable similarity, as well as in their peculiar move- 

 ments ; but it is with the necrophagous beetles 

 (Silpka, Linnaeus) that the greatest number of relation- 

 ships may be perceived, and which become so striking 

 amongst some of the smaller species, that entomolo- 

 gists have been perplexed to assign them to their 

 true location. The genus Micropeplus may be cited 

 as an instance. The head is generally large and flat ; 

 the jaws strong ; the thorax as broad as the abdomen ; 

 the wing-covers cut off square at the extremity, and 

 the abdomen, instead of having its upper surface of a 

 membranous or coriaceous texture, as it is in those 

 beetles which have this part of the body entirely 

 covered by the wings and wing-cases, is scaly both 

 on its upper and under side. 



The Devil's Coach-horse, as the insect is often 

 termed, Staphylinus (Ocypus) olem of Linnaeus, may 

 be mentioned as one of the most common, and at the 

 same time largest, species of the sub-section. It is of 

 a dull black colour, with pale reddish wings, and is 

 about an inch long. It is often to be seen running 

 along footpaths, and in obscure places, such as out- 

 houses, damp cellars, &c. When alarmed at the 

 approach of danger, it assumes a most ferocious atti- 

 tude ; the jaws, which are very large and hooked, are 

 opened wide, ready to seize the approaching object ; 

 the abdomen is thrown over the back, and from its 



RACHELYTRA. 



extremity are protruded not only the pair of conical 

 pilose appendages above noticed, but also several 



Gserius Olens. 



white fleshy vesicles, from which a subtle vapour is 

 emitted, which has a very disagreeable scent. M- 

 Dufour, whose researches upon the internal anatomy 

 of insects are almost unrivalled, and have been al- 

 ready alluded to in this work under the article 

 BOM'BARDIER BEETLE, has published a description 

 of the apparatus producing this vapour in the 8th 

 volume ot the " Annales des Sciences Naturelles." 

 The abdomen is endowed with very considerable 

 powers of motion, being capable of inflexion in almost 

 every direction ; and it is by its assistance that the 

 large wings are folded and unfolded with surprising 

 quickness. We have noticed some of the philonthi, 

 &c., expand their wings, and take flight almost as 

 quickly as a common fly ; when on the wing they are 

 equally agile, and they run with great swiftness. It 

 has been stated that these insects feed upon others 

 which they find in the places of their resort, carrying 

 on a continual war with them, sometimes surprising 

 them in their retreats, and at other times pursuing 

 them with great ferocity. That they are very vora- 

 cious is unquestionable ; and their activity, and the 

 powerful structure of the different parts of their 

 mouths, fully confirms this opinion ; but their voracity 

 appears to us to be applied, not to living, but to dead 

 animal or vegetable matter ; and hence a minute ex- 

 amination of their mouth, and especially of their lower 

 jaws, prove that they possess a very different structure 

 from that which insects which prey upon others in 

 a living state are known to possess. They are found 

 under ground, in manure, under dung, and on fungi, 

 beneath stones, &c. ; and the opinions relative to 

 their habits of feeding upon decaying animal or vege- 

 table matter are confirmed by some circumstances 

 connected with this kind of habitation. We are aware 

 that the opposite opinion has been maintained by 

 the great observer of insects, Dr. Geer, who relates, 

 that having presented a fly to a large species of 

 Staphylinus, the latter seized" it at once, and at length 

 tore it in pieces with its teeth ; but we do not hesitate 

 to state, that if one of these insects be confined, and 

 even a bit of wood or paper be presented to it, ihe 

 result would be the same. The circumstances to 

 which we would more particularly allude result from 

 the geographical distribution of insects, and the ana- 

 logy existing between the manners of the brachelytra 

 and other insects which feed upon decayed vegetable 

 or animal food. 



Who is there that has not, in his twilight rambler, 

 observed the shard-borne beetles (Geotrupes ster- 

 corarius) flying about some particular spot, uncon- 

 scious of every object, and dashing against whatever 

 mny be in their way, with all the blindness of a beetle, 

 their numbers increasing every minute ? This assem- 



