2 24 COLEOPTERA 



shapes, and very peculiar structures of the antennae and maxillary 

 palpi. Owing to the consolidation of some of its segments, the 

 abdomen frequently appears to have less than the usual number. 

 In the curious sub-family Clavigerides, the antennae may have 

 the joints reduced to two or even, to all appearance, to one ; the 

 tarsi suffer a similar reduction. There are about 2500 species of 

 Pselaphidae known ; many of them have never been found outside 

 the ants' nests ; very little, however, is known as to their natural 

 history. It is certain that some of them excrete, from little 

 tufts of peculiar pubescence, a substance that the ants are fond 

 of. The secretory patches are found on very different parts of 

 the body and appendages. Claviger testaceus is fed by the ants 

 in the same way as these social Insects feed one another ; the 

 Claviger has also Ijeen seen to eat the larvae of the ants. They 

 ride about on the backs of the ants when so inclined. The 

 family is allied to Staphylinidae, but is easily distinguished by 

 the rigid abdomen. Only one larva — that of Che^muim Mtuher- 

 culat'um — is known. It appears to be very similar to the larvae 

 of Staphylinidae. The best account of classification and structure 

 is that given by M. Achille Eaffray,^ who has himself discovered 

 and described a large part of the known species. 



Fam. 19. Staphylinidae. — Elyti-a very short, leaving cdivays 

 some of the aldominal segments exposed, and covering usually only 

 tioo of the segments. Abdomen usually elongate, with ten dorsal, and 

 seven or eight ventral segments ; of the latter six or seven are usually 

 exposed ; the dorsal plates as hard as the ventral, except sometimes 

 in the case of the first tivo segments ; the segments very mobile, so 

 that the abdomen can be curled upiaards. The number of tarsal 

 joints very variable, often five, hut frequently as few as three, and 

 not cdivays the same on all the feet. Staphylinidae (formerly called 

 Brachelytra or Microptera) is one of the most extensive of even 

 the great families of Coleoptera ; notwithstanding their diversity, 

 they may in nearly all cases be recognised by the more than 

 usually mobile and uncovered abdomen, combined with the fact 

 that the parts of the mouth are of the kind we have mentioned 

 in Silphidae. The present state of the classification of this 

 family has been recently discussed by Ganglbauer." At present 



' Ecv. ent. franc, ix. 1890. 

 Die Kdfer von Mitteleuropa : II. Familienreihe, Staphylinoidea. Vienna, 1895 

 and 1899. 



