1)86 SERIES III. RERRICORNIA. 



1308 (3969). Heterocerus pusillus Say, .Tnurii. Phil. Acad. Nat. Sci., HI, 

 1823, 200; ibid. II, li'S. 



Obloiig, moderately convex. Dull yellow to pale sooty-browu, either 

 uniform in color or with a broad darker median band extending from base 

 of head to tips of elytra ; epipleura and legs pale. Elytra parallel, not sub- 

 stria te. Length 2-2.5 mm. (Fig. 256, (7.) 



Putnam and Crawford counties, scarce; frequent on border of 

 pond near University farm east of JVIitcheil. July 10-August 7. 

 Readily known by its small size and absence of usual yellow spots 

 on elytra. 



Series III. SERRICORNIA. 



This series is primarily distinguished, as its name indicates, by 

 the serrate or saw-tooth character of the antennae. The serrate an- 

 tenna is, like the filiform, usually slender and of nearly the same 

 width throughout, but differs in having each joint project more or 

 less inwards, this projection being sometimes so long as to form 

 ^vhat is called the pectinate or comb-toothed antenna. As we have 

 already noted, some of the families connect so closely with those of 

 the Clavieomia that they are included in both tables. In all but 

 two the tarsi are 5-jointed. 



Their food is variable in character, but consists for the most 

 part of either living or decaying wood or other vegetable matter, or 

 in those species with soft body covering, mainly of larvae, small 

 worms, snails and other living matter. All the families of the series 

 a,re represented in Indiana. 



KEY TO FAMILIES OF SERHICOENIA. 



a. First and second ventral segments firmly united; antennae serrate, never 

 elongate (pectinate in the male of Xenorhipix) ; tarsi with mem- 

 branous lobes beneath ; prosternal spine received in a cavity of the 

 niesosternum ; thorax fitting closely to the elytra. 



Family XXXIX. BupRESTiDiE, p. 776. 

 (Id. Ventral segments all free and movable. 



/(. Tarsi 4-joint('d ; antennas short, terminal 'joints thicker (flabellate 

 in h'liiiiidiniilnis) ; form cylindrical; length less than ?..'> mm. 



Family XLVII. Cioitlt:, p. S!).l. 

 hi). Tarsi in part or wholly 5-.iointed. 



r. Hind tarsi 4-.1ointed, the others 5-.1ointed ; form oval, convex; 

 length less than ;! nun. Family XLVIII. Si>iiindid/e, p. 001. 



<-r. Tarsi all 5-.iointed. 



rl First .loint of tarsi very short and imperfectly separated from 

 the second; antennal club .S- or 4-.iointpd, first ventral segment 

 nol elongated (subfamily BnxtrichiiHi'') ; antennal club 2- 

 .lointcd, first ventral elongated (subfamily Liicthiw). 



Family XJAV. Bosteichid.e, p. Ssil. 

 lid. I'ii'st joint of tarsi distinct (except in some ClcrUhr). often 

 longer than (be scccmd ; first ventral not elongate. 



