1882.] O^lO [Jayne. 



changes. The pohit to which I woukl emphatically direct atteution is 

 that since radiations are known to be moving in space apart irom ponder- 

 able bodies and subject to reflections, it is possible so to deal with them as 

 to completely alter their destination and successfully interfere with all 

 results flowing from Prevost's law of exchanges. It also seems to me 

 that the exactness of the second law of thermodynamics depends, as far as 

 radiations are concerned, upon that of this law of exchanges. 



Cinciimati, May IBth, 1882. , H. T. E.] 



Revision of the Dermestid ce of the United States. By Horace F. J((ijne, M. D. 

 ( With four Plates.) 



{Bead before the American Philosojjhical Society, June IGth, 1SS£.) 



Many years have elapsed since the small family of Dermestidoe, as rep- 

 resented in our fauna, has received careful study. The addition of new 

 genera and species, and the confusion existing among those already well 

 established, have suggested that a review of the entire field, in the light 

 of modern entomological progress, would be useful to the student. In 

 the following pages differences of structure have been recognized, as far 

 as possible, as the only true and constant characters by which to separate 

 species. The arrangement of genera is, substantially, that already well 

 known, save only the necessary alterations incident to the introduction of 

 two new genera. The specific classification is, almost entirely, original. 

 Dr. LeConte, in addition to very many other favors, has kindly off"ered, in 

 my absence, to read the proof of the following pages. 



DERMESTID iE. 



Head variable in size, deflexed ; front variable in width, a single ocellus, 

 or simple lens, at middle, except in Byturus and Dermestes ; epistoma 

 usually very short, coriaceous, on the same plane as the front except in 

 Axinocerus, in which it is long and retracted ; labrum distinct, mandibles 

 short, simple, except in Byturus in which they are dentate, maxillaj with 

 the base exposed, with two lobes of variable form, palpi small, slender, 

 four-jointed ; mentum quadrate, usually corneous ; ligula simple, palpi 

 three-jointed. Eyes usually prominent — exceedingly in Byturus — mod- 

 erately coarsely granulated, rounded, entire, except in certain species of 

 Trogoderma, Anthrenus and Orphilus, where they are more or less deeply 

 emarginate in front. 



Antennae inserted in front of the eyes, usually eleven -jointed, variable 

 in Anthrenus, nine-jointed in Dearthrus, ten-jointed in a foreign genus, 

 Hadrotoma ; terminated by a large club, which is quite strongly serrate 



