SAW HORNED WOOD-BEETLES. 95 



ous beetles) inhabit wood and bark in an advanced state of decay. In 

 accordance with this position, they are usually the first insects to attack 

 trees which have been injured by sun-scald, or which have otherwise 

 had their vitality weakened. 



The following are the genera of Eapivstiihe : 



A. Hind coxal plates* much widened at their inner extremities. Body oblong and somewhat de- 

 pressed, and more or less elliptical or narrowed at the two extremities. Size usually large or 

 medium. (Jiuprentides proper.) 

 B. The epimera (or hinder side pieces) of the metasternum triangular and exposed ; prosternum 

 acutely angulated behind. 

 C. Mesosternum and metasternum united without suture. First .joint of the hind tarsi as long 



as the second and third united. Size largo or very lai-ge Ciialcophoka, 7 sp. 



C C. Mesostenial suture distinct ; size rather large or medium. 

 D. Elytra tapering to a point and slightly separated at their tips ; 1st joint of hind tarsi scarcely 



longer than 2d Dicekca, 24 sp. 



D D. Elytra moderately narrowed behind. 1st tarsal joint elongated Buprestis, 2:i sp. 



B B. Epimera of the metasternum partly covered by an anterior prolongation of the margin of tlie 

 abdomen. Prosternum acutely angulated behind. 

 E. Front with a pit or depression for the insertion of the autennse. Size moderate : 



Chrysobothris, 4:5 sp. 

 E. Front without pit. Size small. 



F. Thorax waving at its junction with the elytra Mblanophila, 10 sp. 



F F. Thorax cut straight across behind Anthaxia, 14. 



A A. Hind coxal plates but little widened at their inner extremities. Size never above medium; 

 usually small or very small. 



G. Front without pits for the insertion of the autenuie. Thorax straight behind. Scu- 

 tellum none. Body clothed with short erect hairs. Colors often vaiiegated : 



ACM^KODEKA, 23 Sp 



G Gr. Front pitted for anteuuaj. Thorax angulated behind. Scutelhira distinct. Body not 

 hairy. 

 H. Body elongated, narroW^, almost cylindrical. Prosternum without grooves for the 



reception of the antenna Agrilbs, 40 sp. 



H fl. Body short and broad. Prosternum with grooves for the antennas. Tarsi very 

 short. 



I . Body ovate ; scutelliun small ; tibia> slender BitACHYs, 8 sp. 



II. Body sub-triangular ; scutel large; tibise dilated Metonius, 2 sp. 



The largest N. A. species of Buprestis is the Chalcophora virginiensis 

 of Drury, nearly or quite an inch in length, of a dark coppery or black- 

 ish color, and a very uneven surface, caused by elevated lines and de- 

 pressed square-shaped spots. The larva inhabits the trunks of different 

 kinds of pine trees, and the perfect insects are to be found, therefore, 

 only in pine growing regions. The Dieerca divaricata, Say, is three- 

 (|uarters of an inch or more in length, copper colored, with a granulated 

 surface. It is distinguished at once by its tapering elytra, separated at 

 the tips. Its larva bores into the trunks of cherry and peach trees. 

 We have another, smaller and more obscure species, the D. lurida, Fab., 

 the larva of which inhabits the hickory. The Chrysobothris femorata, 

 (Fig. 42) an obscure bronze-black species, rather less than half an inch 

 in length, is the parent of the well known flat-headed borer, so injurious 

 to apple trees, and also to the soft maple. 



* The hind coxal plates are the flat and narrow transverse pieces which border the under side of the 

 thorax behind, and are separated by a suture from the metasternum. They are marked C X P in 

 Fig. 3. 



