334 FAMILY XI. STAPHYLINID^. 



Family XL STAPITYLINID^B. 

 THE ROVE BEETLES. THE SHORT-WINGED SCAVENGER BEETLES. 



A very large family of slender-bodied, small or medium-sized 

 beetles having the elytra truncate and very short, leaving always 

 some of the abdominal segments exposed, and covering usually only 

 two or three of them. The abdomen, both above and beneath, is of 

 corneous or horn-like texture, yet very flexible, and when the in- 

 sect is disturbed it is turned up over the back as if the beetle were 

 about to sting. However, they are perfectly harmless, though some- 

 times disagreeable on account of emitting an odorous fluid from the 

 tip of the abdomen. The ventral segments are eight (rarely seven) 

 in number, while there are ten dorsal ones. The wings are usually 

 fully developed, often exceeding the abdomen in length, and when 

 not in use are folded beneath the short elytra. 



In addition to the characters mentioned, the Staphylinidae have 

 the labial palpi three-jointed except in Tribe I ; maxillary palpi 4- 

 jointed (5-jointed in Aleochara} ; mandibles long, sharp and sickle- 

 shaped, usually crossing one another at tips when at rest; an- 

 tennas variable in insertion and form, 11- (rarely 10-) jointed; 

 mesosternum short, its sidepieces large; metasternum rather large, 

 with narrow sidepieces; front coxre usually large, conical, promi- 

 nent and contiguous, the coxal cavities rarely closed behind; hind 

 coxae contiguous except in the second subfamily; tarsi usually 5- 

 jointed, rarely 4- or 3-jointed. 



In habits the Staphylinids are to be classed as beneficial, as they 

 feed upon decaying animal and vegetable substances, and thus not 

 only act as scavengers, but also aid in reducing the manure heap, 

 and the manure when spread, into a more available form of plant 

 food. The larvae, except in the absence of wings, resemble the 

 adults both in structure and habits, and together with them occur 

 beneath bark, in fungi and in decaying plants, while some are guests 

 in the nests of ants, being reared and attended as carefully while 

 young, as are the young of the ants themselves. 



Sharp says that "it is probable that one-hundred thousand spe- 

 cies or even more of StaphylinidcP are at present in existence." 

 This may be an exaggeration. But 9,000 species are at present de- 

 scribed, 1,500 of which are from the United States alone, and many 

 new ones are turning up each year. As in the other families, the 

 present paper treats only of those which have been taken in the 

 State, or which, from their known range, should occur. It is prob- 

 a.ble that fully half as many more really occur, many of which are 

 at present unknown to science. The literature treating of the 



