NORTH AMERICAN COLEOPTERA. 303 



PH.KDROilllJS Clark. 



Plisedroiniis Waterlioiisei CI. Cat. Haltic. p. 68. 



The type now in the British Museum has no locality attached to 

 it, and, as the insect is of comparatively large size and unknown to 

 Dr. Horn, as it was likewise to Crotch, considerable doubt is attached 

 as to the locality (Carolina) given by Clark being correct. The 

 species has a flavous thorax, not impressed with a bsisal transverse 

 groove, differing in this respect from Pachyonychiis and the elytra 

 are black, shining, and very finely punctate-striate. 



I need only add here, that, although the structure of the anterior 

 coxal cavities in regard to their open or closed state, have been em- 

 ployed by Chapuis as the preliminary division of the Galerucidce, 

 this character must be used with caution, since instances occur in 

 whicii the same species possesses closed cavities in one specimen and 

 open ones in others. Yet these cases are exceptions, and it seems 

 that the closed cavities in the group of Monoplatl go hand-in-hand 

 with punctate-striate elytra (as already pointed out by the late von 

 Harold), and, as already remarked, HamleUa must be removed fronl 

 this group of Halticinie. 



Supplementary Notes. 



BY GEO. H, HORN, M. D. 



As correctly shown by Mr. Jacoby, Hamletia {Pdchyomjchis % Clk.) 

 cannot be referred to the Monoplati, but to the Q^klionychi as de- 

 fined l)y Chapuis and adopted in the Class. Coll. N. A. pp. 849 and 

 851. The posterior tibite have a sinuation on the posterior edge 

 above the insertion of the tarsi as in the genera Physodactyla and 

 Ql^dionychis. The penultimate joint of the maxillary pali)us is, at 

 apex, about as broad as long as in Physoma from Qildionychis and 

 Physodactyla it differs in having absolutely simple claws and the 

 head not deeply inserted in the thorax. 



At the time of the preparation of the Classification the species 

 was unknown to us. Since then a good specimen has come to me 

 and the antennae are seen to be parti-colored, the four basal joints 

 yellowish testaceous, the next four black and the three terminal yel- 

 lowish white. 



As the name Pachyonychus jjaradoxus had been already used by 

 Melsheimer, the practically identical name given by Clark for the 



