PACHYONYCHIS. 63 



(like the anterior) bifid and simple, not armed at its inner surface 

 with any second tooth. 



This genus has several well-defined characters, which, combined, 

 abundantly separate it from allied forms. In the antennae the 

 second joint is longer and narrower relatively than in other groups, 

 and the fourth joint is rather longer than the third. The sides of 

 the thorax are coarctate, in front and near the base ; and in the an- 

 terior tarsus the first joint is broadly dilated, and the second joint 

 minute. 



1. Pachyonychis paradoxus. (TAB. II. fig. 7.) 

 Pachyonychis dimidiaticornis, Dej. Cat. 



P. oHongo-ovatus, latus, depressus, punctatus, nigro-ceneus ; capite 

 brevi, haud producto, inter oculos transverse foveolato, impunctato, 

 glabro ; thorace quadrato, sed antea constrieto, impunctato, nitido, 

 nigro ; elytris latis, depressis, punctatis ; antennis robustis, ad 

 apicem incrassatis, art. \-4flavis, 5-Sfuscis, 9-11 pallideflavis ; 

 pedibus flavis, tar sis anterioribus fusco suffusis. 



Long. corp. 1-| lin., lat. f lin. 



Oblong-ovate, broad, depressed, thickly punctate, of a dark olive- 

 green colour which approaches to black. Head short, transverse, not 

 produced between the eyes : between the eyes is an obsolete, trans- 

 verse, irregular groove, which is connected medially with the base 

 of the antennae by a fine longitudinal fovea; the two, together, 

 forming the impression of the letter T : the surface impunctate, gla- 

 brous. Thorax quadrate in general form, but considerably con- 

 stricted anteriorly; this constriction, commencing from the middle 

 of the sides, gives the appearance of a very broad truncation of the 

 anterior angles ; the anterior angles subacute, very much depressed ; 

 the sides marginate, more distinctly near the posterior and anterior 

 angles ; surface impunctate, shining, black. Scutettum triangular, 

 large, and distinct ; the sides slightly rounded, impunctate. Elytra 

 broader than the thorax, depressed; the sides broadly marginate; 

 the surface thickly and coarsely punctate throughout. Antennae 

 robust, incrassated towards the apex ; the first joint elongate, and 

 dilated near the apex ; the second ovate ; the third as narrow as, 

 but rather longer than, the second ; from the fifth to the eleventh 

 short, and dilated ; in colour, the first to the fourth flavous (the first 

 and fourth being slightly suffused with fuscous), the fifth to the 

 eighth dark fuscous, the ninth to the eleventh very pale flavous. 

 Legs flavous throughout, the anterior tarsi being suffused with 

 fuscous. 



North America (Philadelphia). In the collection of M. Chevrolat. 



