LAND SCAVENGER-BEELES. 63 



Family XV. ANISOTOMID^. 



This family of minute Coleoptera is composed chiefly of the genera 

 Anisotoma and Agathidimn, of Illiger. The first term signifies unequal 

 division, and has reference probably to the structure of the antennal 

 club, which, in the subfamily Auisotomides, consists of five joints, the 

 secoud of which is the smallest. Mr. Westwood regards the second genus 

 as the type of the family, which accordingly he denominates Agathi- 

 DiiD^. But the other term is adopted by the most recent writers. 

 These insects are remarkable for their very small size ami their sub- 

 globular bodies, those of the sub-family Agathidiides having the power 

 to contract the head and thorax upon the abdomen so as to form a little 

 ball. The thorax is orbicular with thin edges, like that of the compara- 

 tively gigantic Silphidse, with which, indeed, they are united as a sub- 

 family by the principal modern authorities, such as Erichson, Lacor- 

 daire and LeConte. 



These minute insects are found mostly in fungi and rotten wood, and 

 can frequently be caught flying in the evening. 



Number of described N. A. species, tbirty-five. 



Family XVI. PHALACRID.E. 



A small family of very small, convex, shining black insects, some- 

 times two-spotted or tipt with red ; formerly confounded with the pre- 

 ceding family, but separated from it by a Swedish naturalist, Paykull, 

 under the generic name of Phalacrus, a word meaning bald-headed, and 

 suggested probably by the rounded, shining aspect of these beetles. 

 They differ from Anisotoma in having but three joints in the club of the 

 antennae, and from Agathidium in not being contractile, nor in having 

 the hind margin of the thorax overlay the base of the elytra. They dif- 

 fer also in their habits from the foregoing family, being usually found 

 upon flowers. 



Twenty N. A. species have been described. 



Family XVII. TRICHOPTERYGID.E. 

 This family surpasses the two former in the minuteness of its species 

 — the largest not exceeding small pin-heads in size, and the smallest 

 not being one-quarter as large— the species varying from about one- 

 twentieth to one-seventieth of an inch in length. Nevertheless, it is one 

 of the wonders of nature that within the almost infinitissimal compass 

 of their minute beings are contained all the divisions, the limbs and or- 

 gans of the most gigantic species. The family is founded upon the 

 genus Trichopteryx, of Kirh J— Sj term meaning hairy-winged, in reference 

 to the peculiar construction of the inferior or true wings, which are com- 



