AMERICAN COLEOPTERA. Ill 



The genera are separated in the following manner : 



Mentum tooth large, nearly as long as the lateral lobes, emarginate. Thorax 

 without lateral seta. Elytra with variolate fovese, not striate. ..Elaplirus. 

 Mentum tooth short bifid at tip. Thorax with lateral setigerous puncture. 



Head not suleate, elytra with feeble striae of punctures Diachila. 



Head with deep lateral grooves, elytra striate with interstrial foveiB...Bletliisa. 



Elaphrus. — The affinities existing between this genus and Opisthius 

 have been referred to in the proper place. It is remarkable that the 

 lateral seta of the thoi-ax is absent in all the species of this genus except 

 viridis Horn, which is the only one in our fauna with the thorax wider 

 than the head including the eyes. In the larger species the nudes have 

 four joints dilated, in the smaller but three. 



Diachila. — Two species occur in our fauna, arctica Gyll., common 

 to both Europe and America, and mhpolaru Lee, from Hudson's Bay. 

 The anterior tarsi of the male have four dilated and spongy pubes- 

 cent joints and in mhpolaris the middle femur has a small tooth near 

 the base. 



Blethisa. — Four joints of the anterior tarsi are slightly dilated and 

 spongy pubescent beneath in the male, and in quadricollis Hald., the 

 anterior femora have an acute tooth beneath. 



Tribe VIII. Loricerini. 



Anteunaj sleiuler, base free, first four joints glabrous, first joint elongate, third 

 longer than second, joints 2—6 with long bristles in front. Eyes round, prominent. 

 Head forming a distinct neck and with one supra-orbital seta. Labrum moderately 

 prominent, arcuate in front. Maiulibles thin, curved, acute at tip, without setiger- 

 ous puncture. Maxillae with a moderate foliaceous expansion at base which bears 

 long cilise, inner lobe hooked at tip, sparsely ciliate within, outer lobe with slender 

 joints, palpi slender the last joint longer than the preceding and acute. Mentum 

 moderately emarginate with an obtuse tooth, basal suture distinct. Ligula not 

 prominent, slightly prolonged in front and bisetose, the paraglossse adherent in 

 their entire length and not longer, the palpi slender the last two joints nearly 

 equal, the penultimate bisetose in front. Thorax transversely cordate, with a 

 single setigerous puncture at the side behind the middle. Body not pedunculate, 

 scutellum distinct. Elytra margined at base, sides narrowly intlexed, lateral margin 

 entire but with a distinct internal plica. Prosternum not prolonged behind, the 

 anterior coxal cavities closed. Mesosternum oblique not carinate in front. Meta- 

 sternal side pieces distinct the suture between them well marked, posterior coxa; 

 contiguous. Legs slender, middle and hind tibiae spinulose externally, anterior 

 tibise deeply emarginate within, the inner spur remote from the apex. Tarsi 

 slender. 



The anterior tarsi of the male have three joints rather broadly dilated and 

 densely spongy pubescent beneath. 



This tribe contains but one genus Loricera, in our fiiuna, with 

 which ElUptosoma Woll., a Maderan form has been associated. These 

 are said to differ in the absence of metasternal epimera in the former 



