76 THE ORDER OF COLEOPTERA. 



Family XXIV. PSELAPHID^. 



This is a family of minute beetles, generally less than a tenth of an 

 inch in length, and is founded ui^on the genus Pselaphus, of Ilerbst, a 

 term derived from the Greek pseJcqjhus — to feel, in allusion to the greatly 

 [Fig. 30.] developed palpi or feelers. They are found in the same 

 situations as the Staphylinidte, and resemble them in the 

 shortness of the elytra, which usually cover only about half 

 of the abdomen. In their form, however, they are wholly 

 different, being short thick-bodied beetles, with the abdo- 

 men much larger than the thorax. The antenua3 are clavate 

 or capitate, and the maxillary i^alpi are very long and cla- 

 vate, often equalling the antennae in length. The tarsi are 

 PsELAPHus:—!, apparently two-jointed, but really three-jointed, the first 



beetle ; 2, maxilla- . , . ,, t -, /^ i i i o. i 



ry palpus ; 3, tar- joiut Dcing vcry Small. Like some of the larger otapliy- 



sus, showing rai- ,, . i . , . 



nute basal articn- linid?e, thesc vcry Small insects are predaceous in their 



lation, all matriiiti- , . . *" • -, ■, • • ^ 



ed— after AVestw. habits, subsistiug iipou acari and other mmute animals. 

 Some of them are found in ants' nests. A synopsis of the Pselaphidae 

 of the United States is given by Dr. E. Brendel, in the sixth volume of 

 the Proceedings of the Ent. Soc of Philadelphia, where eighty species 

 are briefly described. 



Fourth Sub-section. f'ECTIlVICOIlJNTES. 



Antenna; pectinate or comb-toothed ; subsist mostly upon the sap of trees. 



Tribe VI. 



STAG-BEETLES. 



This sub-division and tribe are composed of the single family of Lu- 

 canid* or Stag-beetles, distinguished by their pectinate or comb-toothed 

 autenuie, which are also strongly geniculate or elbowed ; by the project- 

 ing mandibles, which, in the males, are often enormously developed and 

 branched, from which these insects have received their common name 

 of Stag-beetles ; and by their size, which is never below the medium, 

 and is generally large or very large, some species being upwards of two 

 inches in length, including the mandibles. 



These insects are closely allied to the Lamellicorn beetles which fol- 

 low, and are considered by many authors as holding the rank of only a 

 subdivision or family of the latter. Most modern authors, however, 

 treat them separately. The principal differences may be expressed as 

 follows : 



Pectinieornes. Antennae elbowed, the club composed of fixed trans- 

 verse teeth. Mandibles of the males often greatly developed. The ner- 

 vous ganglia distributed through the abdomen as well as the thorax. 

 LarviB without transverse wrinkles upon the segments ; anal opening 

 lengthwise. 



