308 GEO. H. HORN, M. D, 



slender the anterior dilated in the male, these four-jointed, the middle and 

 posterior three-jointed. Tarsi of female three jointed on all, the first and last 

 joints moderately long and equal, the second short. 



With the antennal grooves beneath the head and the dissimilarity 

 of the tarsi in the sexes, there can be no doubt that this genus should 

 be placed near Agathidium and not Colenis. The antennal club is 

 however somewhat like that of the latter genus, so that there may be 

 some doubt as to whether it should be called three- or five-jointed, 

 it is in much the same condition that we find in several species of 

 Agathidium in which the seventh joint is a little larger than the 

 eighth. 



The number of the tarsal joints in the male is a repetition in the 

 present series of genera of the same character in Agaricophagus, in 

 which however the tarsi are similar in the two sexes. That they are 

 three-jointed on all the tarsi in the female has been verified by an 

 examination under the compound microscope, a matter rather diflBcult 

 to do in so small an insect. 



A. Ifevis Lee. — Oval, very convex, very little longer than wide, piceous, 

 shining, surface without sculpture. Thorax with margin and base translucent, 

 hind angles rectangular. Body beneath rufous, smooth. Length extended .Oi — 

 .06 inch; 1—1.5 ram. (PI. VII, fig. 15). 



Male. — Anterior tarsi moderately dilated, four-jointed, middle and posterior 

 tarsi three-jointed. 



Female. — Tarsi slender, three-jointed on all the feet. 



The form of this insect is that of a diminutive Agathidium re- 

 sembling rotundulum or politnm. 



Occurs in Canada, Illinois, Georgia, Louisiana, but rare. 



Tribe Nl.— Clamhini. 

 Anterior coxse conical, moderately prominent, contiguous, with moderate 

 trochantin, the cavities angulate externally and closed behind. Middle coxae 

 separated by the mesosternum in Empelus and by the fine carina in the other 

 genera. Posterior coxse contiguous with plates covering the thighs, partially 

 ia Empelus or completely in Clambics and Calyptomerus. Antennae of eleven, 

 ten or nine joints variably inserted, either contiguously to the eyes (in Clambus) 

 or distant, but not under a frontal margin. Tarsi four-jointed, tibiae with- 

 out spurs. 



The structure of the posterior coxae affords the only means of 

 separating this tribe from the rest of the family as a whole. By the 

 structure of the anterior coxae and their cavities the Auisotomini are 

 the only close allies. 



The posterior coxae in two of the genera have quite broad plates 

 arcuately narrowed within which cover completely the posterior legs 

 in repose. In Empelus however the plate is very narrow on the outer 



