FAMILY LV. TKNEBRIONIIVK. 



XIX. PLATYDEMA Lap. 1831. (Gr., "broad + body.") 



Small or in odium-sized, broadly oval convex species having the 

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

 epipleuraj entire; mesosternum concave; last joint of maxillary 

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

 intercoxal process of abdomen triangular, acute. They occur es- 

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

 neath bark. About 16 species are known from the Tnited States, 

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



KEY TO INDIANA SPECIES OF PLATYDEMA. 



(i. Head with horns or tubercles; front concave. 



li. rpper surface black, shining. 2332. EXCAVATUM. 



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



2333. ERYTHROCERA. 



mi. Head without tubercles or horns. 



<: Thorax dull red, elytra black. '-.\'.'A. RUFICOLLE. 



re. Thorax and elytra black. 

 '/. .Surface opaque. 



e. Elytra without red spots. 



/. Antennae wholly pale. 2:>.'.!5. BUFICORNE. 



//. Antenna? black, three basal joints pale. 233G. FLAVIPKS. 



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



2337. ELLIPTICUM. 

 tl<l. Surface shining black. 



//. Prostermnn horizontal, its apex prominent. 



//. Head with distinct transverse groove and frontal impress! n. 



AMERICA MM. 



lilt. Head without transverse impression. 



i. Thorax very sparsely punctured. 2338. L.EVIPES. 



ii. Thorax and intervals of elytra densely punctured. 



2339. MI CANS. 



Of/. Prosteruum convex between the cox;e, its apex deflexed and ob- 

 tuse. 



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



5 mm. 2340. PICILABRI'M. 



././'. I'roadly oval; larger, G-7 mm. 2341. SI'SCOST-ATI'M. 



: ' f '2:\:>'2 (7.~i10). PLATYDEMA EXCAVATUM Say, Journ. I'hil. Acad. Nat. Sci.. 



III. 1824. 207; ibid. II, 157. 



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

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

 Cylindrical horns between the eyes; front deeply concave between the bases 

 of the horns; hecfd ofTemale 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- 

 lily convex, minutely punctured. Length 4.r-r>..~ mm. 



TlnMn.'-li(!ut the State; common. Januarv 11-October 14. 



