304 MARTIN JACOBY 



insect at present under consideration was dropped by Crotch and 

 Haniletia proposed. 



Hainletia diinicliaticornis Crotch, Proc. Acad. 1874, p. 59. 



Pachyonychis paradoxus \\ Clark, Catal. Haltic. B. M. p. 61, pi. 2, fig. 7. 



The first use of the name in description of Pachyonychus jwara- 

 doxus was by Melsheimer, Proc. Acad, iii, p. 168, and as remarked 

 by Crotch, the name must remain. The species was certainly not 

 known to Chirk, and Mr. Jacoby is the fix'st authority who has seen 

 the insect. 



Pachyonychus Mels. is a true representative of the Monoplati. 

 The maxillary palpi are short and stout, thicker externally, the ter- 

 minal joint obtusely conical. The posterior tibise have two well- 

 defined ridges along the posterior edge which are straight and not 

 denticulate. The tarsal claws are appendiculate at base. The tho- 

 rax is transverse, the anterior angles dentiform, the side not augu- 

 late, the disc deeply transversely impressed in front of the base. 



From these characters, supplementary to those given by Crotch 

 the genus will be seen to be related to Cerichrestus. As the latter 

 has a double spur to the posterior tibise and the surface of body pu- 

 bescent, while there is but one short spur in Pachyonychus and the 

 surface glabrous, the two genera are abundantly distinct. 



The species on which Phredromus has been founded has never 

 been seen by me in any American collection. It is of oblong, par- 

 allel form, thorax yellowish, elytra nearly black. It differs structu- 

 rally from the other two genera, Pachyonychus and Hypolampsis, 

 in having slender maxillary palpi. 



Removing Hamletia {Pachyonychis X Clark), as suggested, to the 

 (Edionychi, the genera of Monoplati, on p. 350 of the Classification 

 of the Coleoptera of N. A. may be modified as follows : 



Maxillary palpi slender; posterior tibiie with a double terminal spur. 



Plis^dronius. 

 Maxillary palpi stouter to tip ; posterior tibise with a single terminal spur. 

 Posterior tibise longitudinally bicarinate, thorax transversely impressed in 



front of base; body glabrous Pacliyonyclius. 



Posterior tibise feebly unicarinate; thorax not impressed ; body hairy. 



Hypolampsis. 



The species at present included in Qildionychis must be separated 

 into several genera already described, and will remain for a future 

 study. The notes already given will enable Hamletia to be separated 

 from QCdionychis as at present constituted. 



