AMERICAN COLEOPTERA. 71 



Trachypachys Gibbsi, Lee. Pi-oc.Acad. ISGl, p. 339.= 7*. oaA/omicws, Motsch. 

 he. cit. p. l'J4. • 



OMOPHRON, Latr. 



Several new species of Omophron beiug in my cabinet, I have thought 

 it advisable to define our species by means of short descriptions, 

 so that the student may be enabled to determine them ; for although 

 our species are comparatively few in number, their descriptions are so 

 widely scattered as to be inaccessible to many. 



Our species divide themselves into two groups: 



Group I. — Species broadly oval, shining, elytral strins almost en- 

 tirely eflfaced at apex and indistinct at the sides median thoracic line 

 scarcely evident. Two species are known lahiatum and nitidum. 



Group IT, — Species less broadly oval, less convex and shining, 

 elytral striD3 attaining (very nearly) the apex, latei'al strioo as dis- 

 tinct as the discal. 



Elytra, 14 — striate. 



Strite deep, finely and closely punctured gilae. 



Strioe moderate, punctures rather distant and obliter- 

 ated at apex obliteratum, n. sp. 



Stride faint, punctures large, distant robustum, n. sp. 



Elytra 15-striate. 

 Broadly oval. 



Punctures of elytral strire obliterated at apex dentatum. 



Punctures distinct at apex. 



Lateral margins only, of thorax, pale americanum. 



Lateral, basal and apical margins pale tesselatum. 



Elongate oval, 



Elytral strife not deeply impressed, finely and closely 



punctured ovale, n. sp. 



0. labiatum, Fabr. (Scolytus) Syst. El. I. p. 248: Say (Omophron) Trans. Am. 

 Phil. Soc. vol. II, p. 79, 1S2S; Dej. Sp. 2. 261, 1S26.— Broadly oval, convex, shin- 

 ing; color dark brown or nearly black, lateral margin of thorax and elytra 

 pale, the latter broader at apex. Elytral strife moderately deep at their basal 

 third with rather large but distant punctures; as the strife approach the mid- 

 dle the punctures become effaced and near the apex the strife themselves are 

 totally obliterated, scarcely any trace remaining ; toward the sides the strife be- 

 come also effaced. The pale limb of the elytra in most specimens gradually 

 shades iuto the darker color of the disc, but little tendency being shown to the 

 formalinu of branches or processes as in all our other species. The under sur- 

 face is dark piceous witli the sides and apex of ab<lomen paler. Theprothorax 

 is nearly blackwith the lateral margins pale silvery-white, with coarse sparsely 

 placed punctures more closely approximated at the apical and basal regions. 

 Head black with a metallic lustre near the eyes, anterior margin of front and 

 clypeus brownish, labrura silvery-white. Length .24 inch; 6 mm. 



Middle & Southern States. 



