THE METALLIC WOOD-BORING BEETLES. 795 



Tribe III. MASTOGBNINI. 

 This tribe is repri'sentcd in North Amerioa by the single gi'ims 



XII. ^[astogenk^s Sol. l^i.jl. (Gr., "mother + chin.") 



It in turn is represented in the eastern United States by one of 

 the smallest Buprestids known, subcylindrical in form and having 

 the antennae inserted in large cavities, narrowing the front, which 

 does not expand again in front of the cavities as in Agrilus; mouth 

 small, deflexed but not applied to the presternum ; thorax truncate 

 at base, closely fitting against the elytra; presternum truncate be- 

 fore and behind, with the lateral sutures parallel; scutellum small, 

 triangular; lesis not contractile, claws broadly toothed. 



1511 (4717). Mastogenius subcyaneus Lee, Trans. Amer. Phil. Soc, XI, 

 1859, 254. 

 Subcylindrical. Bluish-black, shining. Head with a lengthwise groove. 

 Thorax one-half wider than long, slightly wider than elytra, convex, sides 

 strongly rounded ; surface, as well as that of elytra, finely and rather 

 sparsely punctate. Elytra with a deep but narrow transverse impression 

 at base, sides parallel, tips obtusely rounded. Length 2-2.5 mm. 



A single specimen taken by sweeping on University farm near 

 ilitchell, Lawrence County, ^^lay 11. LeConte states that it oc- 

 curs rarely on leaves and flowers in the Middle, Southern and West- 

 ern States. 



Tribe IV. AGBTLIXI. 



Small-sized, usually, slender, though sometimes short, broad and 

 flat species, having the 1iody narrowed on apical third. Their chief 

 structural characters are the front strongly nan-owed by the inser- 

 tion of antenna'', then expanded, thus forming two diverging lobes ; 

 front part of head vertical, the mouth inferior and applied to the 

 prostemum in repese; thorax lobed fit base, receiving the convex 

 bases of the elytra; legs contractile; tarsal claws strongly toothed. 

 Six genera are recognized as composing the tribe, four of which are 

 known to be represented in Indiana, while another perhaps occurs. 



KEY TO INDIANA GENEBA OF AGRILINI. 



o. Antennae free, in repose not received in grooves on the under side of 

 thorax. 

 6. Hind tarsi with first joint scarcely elongated. Eupristocekus. 



66. Hind tarsi with first joint as long as the three following. 



XIII. Agrilus. 

 aa. Antennoe received in grooves on under side of thorax near the margin. 

 c. Scutellum small ; tibiae linear. 



