1262 



FAMILY LV. — TENEBRIONIDJE. 



XIX. Platydema Lap. 1831, (Gr., "broad -body.") 



Small or mediiun-sized, broadly oval convex species having the 

 first joint of hind tarsi longer than the two following together: 

 epipleurie entire; mesosternum concave: last joint of maxillary 

 palpi broadly triangular, its inner and outer sides nearly equal; 

 mtereoxal process of abdomen triangular, acute, They occur es- 

 pecially on fleshy fungi about the bases of stomps or trees or be- 

 neath bark About 16 species are known from the United States, 

 ten of which are known from Indiana, while another may occur. 



KEY TO IXDIAXA SPECIES OF PLATYDEMA. 



a. Head with horns or tubercles ; front concave. 



h. Upper surface black, shining. 2332. excayatum. 



TjTj. Upper surface piceous or dark reddish-brown, opaque. 



2333. eeythbocera. 



a a. Head without tubercles or horns. 



c. Thorax dull red. elytra black. 2334. bfjficoixe. 



cc. Thorax and elytra black. 

 d. Surface opaque. 



e. Elytra without red spots. 



/. Antennas wholly pale. 2335. bfttcoknt:. 



ft. Antennas black, three basal joints pale. 2336. fiaytpes. 



ee. Elytra each with an oblique red spot on basal half. 



2337. ELLTPTICFM. 



d(L Surface shining black. 



g. Prosternum horizontal, its apex prominent. 

 h. Head with distinct transverse groove and frontal impression. 



AMERICAN UM. 



hh. Head without transverse impression. 



i. Thorax very sparsely punctured. 233S. i^vepes. 



ii. Thorax and intervals of elytra densely punctured. 



2339. mi cans. 



gg. Prosternum convex between the coxie, its apex deflexed and ob- 

 tuse. 



j. Elongate-oval; black with a bronzed tinge: smaller, not over 

 5 mm. 2340. picilabbum. 



jj. Broadly oval: larger. 6-7 mm. 2341. subcostatfm. 



*2332 ( 7510). Platydema excayatfm Say. Joum. Phil. Acad. Mat. ScL 

 III. 1824, 267 : ibid. II. 157. 

 Broadly oval, convex. Black, shining ; antennas and legs reddish-brown, 

 the latter sometimes piceous. Head of male with two parallel, prominent, 

 cylindrical horns between the eyes : front deeply concave between the bases 

 of the horns : head of female with tubercles instead of horns. Thorax more 

 than twice as wide as long, narrowed from base to apex, surface finely and 

 sparsely punctate. Elytra with rather finely punctured striae : intervals fee- 

 bly convex, minutely punctured. Length 4.5-5.5 mm. 



Thronghont the State- common. January 11-October 14. 



