CETONIIN.E 377 



section has yet occurred in the pahearctic faunal regions. Besides 

 considerable variability within specific or subspecific limits, some 

 parts of the body seem to be peculiarly subject to accidental 

 deformation in this genus. In the type of lacustrina, for example, 

 the funicle of the right antenna is much shortened and thickened 

 and the club reduced to less than half its usual size and thickness, 

 and, in one example of rugosa, the reflexed clypeal edge is very 

 irregular. The tarsi in Osmoderma, because of their even thickness, 

 nearly glabrous surface, suboval joints, with the basal joint short 

 and unmodified, remind us forcibly of those of Dynastes, though 

 they are relatively smaller in size. Lacordaire must have over- 

 looked this genus when he wrote that one of the chief distinguishing 

 characters of the Trichiini is the dorsal invisibility of the mes- 

 epimera. 



The female in the scabra section is generally somewhat darker in 

 color or less metallic than the male and sometimes a little larger 

 in size, with still coarser sculpture, the head flattened above, 

 densely punctato-rugose and with unreflexed clypeal apex, the 

 eyes not smaller than in the male, as they are in eremicola, and the 

 prothorax is relatively somewhat smaller than in the male. Of 

 scabra, I have two females, one from the District of Columbia; 

 the elytra are quadrate, not longer than wide and much shorter 

 than in the male and the pronotum is very closely and coarsely 

 sculptured almost throughout. Of rugosa I have seen about a 

 dozen females, some of w T hich are apparently from Wisconsin, the 

 elytra are longer than wide, though broader than in the male, 

 and the pronotum is more loosely sculptured than in scabra, espe- 

 cially toward base; as usual, the dorsal ridges so developed in the 

 male are very faint or vestigial. Just which is typical scabra, the 

 form indicated above, or that described as rugosa, it is impossible 

 to decide, but the form selected best fits the name. Of lacustrina 

 I have a single female, which greatly resembles that of rugosa, 

 except that the prothorax is relatively larger and broader; it is 

 from Illinois. Of gracilipes the single female before me is smaller, 

 less stout and has a much smaller prothorax than in any of the 

 allied forms; it may prove to be a true species. Nothing is now 

 known to me of the female of the very distinct and interesting 

 delicatula. 



