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NATURAL HISTORY. 



loosely knit the prothorax has extraordinary freedom of motion, to the extent of being capable of 

 turning independently of the trunk ; the sternum, however, presents more completeness and solidity 

 in other of the sub-families, and in the Proteininae resembles that of the family Nitidulidse, in 

 which the coxae of the first and third hind pair of legs rest in transversal sockets. 



The principal recent authors limit the tribe Brachelytra to the single family Staphylinidse. 

 The family is subdivided into eleven sub-families, and the number of known species at the present 

 time does not fall far short of 5,000. They frequent the same haunts as the Carabidse, and are 

 distributed equally with them over all parts of the earth ; they are, however, more varied in their 

 habits. A large number of species are the guests of Ants, and are found only by assiduous search in 

 the underground chambers of those insects. As many as 350 specimens, comprising seventeen species, 

 chiefly of small Staphylinidae, have been found by sifting the detritus of one nest of the Red Ant. 

 Many of them are possibly only tolerated, visitors of the Ants, resorting to the nests only in search of 

 food. Multitudes of species live in the dung of animals, and in decaying animal and vegetable matter 

 of all descriptions, some genera, of curious flattened form, being restricted to the confined spaces 

 under slightly loosened bark of trees, and others to fungi and boleti. Their chief prey in these 

 situations consists of other insects. They shun the daylight, and in the height of summer are 

 scarcely ever seen abroad ; but in early spring, and in warm evenings after sunset, they fly abroad 

 in great numbers, seeking fresh hunting-grounds, and thus disseminating their species over wide areas. 

 The larvae resemble the perfect insects more than is the case in any other family of Coleoptera, 

 affording another indication of the low rank of the Brachelytra in the order. 



FAMILIES PSELAPHID^E AND SCYDM^ENID^E. 



The PSELAPHID.E are a group of very small Beetles of anomalous structure, which bear a certain 

 analogy to the Paussidse, being, like them, of recondite habits, and at least, in some well-established 

 cases the enforced guests of Ants. In both families the antennae display great vagaries of form, and 

 the parts of the mouth exhibit singular variations from the forms ruling in the allied groups. If, 

 however, the hypothesis of anomalous modification be accepted, the Pselaphidffl must be admitted to 

 be modifications of a different type from that which the Paussidae were derived from ; and just as the 

 latter are possibly offshoots of the Carabidae, the present family may be similarly related to the 

 Staphylinidae. Some authors, indeed, class them as a family of the Brachelytra. They have 

 similarly abbreviated wing-covers and horny dorsal segments of the abdomen, 

 but here the similarity ceases ; the mouth-parts differ in the soft membranous 

 texture of the lower jaws and their external lobes ; their abdomen (generally 

 of five segments only) has little flexibility, and the tarsi consist only of three 

 joints. The antennae vary in the number of their joints from the normal 

 number of eleven to six, two, and even a single joint, and are often thickened 

 into a club of various forms. Sometimes they are short and rigid ; at othei 

 times very long and bent into an angle, or elbowed. 



The Pselaphidae are distributed through all climates, being found in the 

 tropics as well as in temperate and high northern latitudes. Many of the 

 more extraordinary forms occur in Australia. We give a figure of one of 

 the English species (Pselaphus heisii) which represents the ordinary shape 

 of the family, and which, like most of the typical species, is found by searching 

 at the roots of herbage on sandy banks, especially near water. The Ant- 

 nest kinds are those which exhibit the strangest aberrations in the number 

 and form of the antennal joints, such as the genus Claviger, in which these 

 organs have only six joints, and all the pai'ts of the mouth exhibit equally 

 curious degradations of structure. These insects are totally blind, external 

 eyes and optic nerves having alike disappeared, and they seem to be helplessly 



dependent on the Ants for sustenance. A well-known British species (Claviger testaceus) is the 

 guest of the Common Yellow Ant (Formica flava], passing its whole life in its nests, and being 

 fed from the mouth of the Ants, and jealously guarded, with the object, as it has been stated, 

 of securing a steady supply of a grateful liquid, seci-eted by the Clavigers from certain curious 



FSELAPHVS HEISII. 



