588 FAMILY XXIV. DKKMKSTID.i:. 



pjii'tly iM)\('i'c(l with MJilc ^urny ov hi-owii s|)()ts coniposcd of iniiiutt' 

 scjilcs Of Iwiirs which iirc cjisily ruhhcd ofi'. When distui'licd thi'y 

 usually "phiy possum." foMiiiu' hai-k Ihcif K\l's and rollin.u' ox'ci" on 

 thcii- ])a('l<s. whcfc Ihcy rc-iiain (luicsccnt foi- s:)tii(' lime. The iuim(^ 

 of the ty|)i!al ucuus. /h i'hk sh s, is dcfivcd from two (Jreck words 

 iiicauiiiL!- "'a skin" and "to dcvoui-." wlicner the counnon nami- of 

 skin-caters or skin heet h's. 



'I'he principal dist in,^uislii!i<^' charactei-s of llie family are the 

 small deflexecl head; e^'cs rounded, with small facets, tlie fi-ont 

 usually with a third simple eye oi- o.-cllus; antenna' short, inserted 

 in front of eyes, usually 11-. someti;nes !)- or lO-joiuted. the last 

 two or three joints forming a large cluh; thni-ax slioi-t. in the ma- 

 jority of species excavated beneath for the reception of the an- 

 tennii^; elytra eovei'itsg the abdomen, not striate; abdomen with ti\'e 

 free venti'al segments; front coxa' i-athei- long, conical or obli(iue, 

 the cavities open behind except in I'l/hinis: middle coxa' oval, 

 obrKMie; hind coxa' slightly se|»arat('d. usually dilated into a plate 

 partly pi'otecting the femora and formed to receixc the latter in 

 repose; legs shoi't. tibia' with distinct spurs; tarsi o-joiuted. claws 

 usually simide. 



The larva' of the majority of Dermestids are brown, active grubs 

 ( l(!thed with long hairs and nsually with a brush of similar hairs at 

 the end of the body. ^Many of them have a |»eculiar gait, I'lnuiing 

 for a short distance, then stopi)ing and vil)rating the hairs with 

 great rapidity. They are nuich more destrnctive than the adult 

 beetles, but at times a|)i)ear to be able to live fo;- long periods with 

 little or no food. 



Between -SOO and 400 s])ecies of I )ei'mest ida' are known, about So 

 of 'which, with numerous varieties, are from North America. Th<' 

 pi-inci])al literature ti'enting of these is as follows: 



Le('oiif( . — "Synf)psis of the Dermestida- of tlu^ T'nited States,'' 

 iv Proc. Phil. Acad. Xat. Sci., VIII, 18r)4, lon-ll:! 



Ja>/)ir. — "Revision of the DermestidiP of the I'uited States." /;/ 

 Proc. Amei'. Phil. Soc. XX, 1882. :U:i-'M7 . 



Casc'l/. — ''l\e\iew of the .\mei'ican Dermestida'," /;/ Joui'u. N. 

 y. Knt. Soc., Vlll. 1!)()(). l:;s Ki."). 



The memlx'i's lA' the family which lia\-e a range including Indi- 

 ana are distriliiited amcniv eight genera. 



KKV TO IXUI.WA (a:XKI{A Ol' IIKUMKS'I in.i':. 



(I. Tarsi willi sccniid aiid tliird Jdinls Inlieil hene.-itli : I'mnl cdxal cavities 

 closed Ix'hiiid; claws armed witii a \[\\-^r hasaj tuntli. ( Fi.ij;. 1221.) 



I. F.YTUKUS. 



