AMERICAN COLEOPTERA. 115 



The tribe as defined by Chaudoir (Bull. Mosc. 1861, i, p. 510), is 

 certainly composed of very dissimilar material and I have removed 

 Metrius to form a distinct tribe the reasons for which will be found in 

 the proper place. 



The genera referred to this tribe by Chaudoir (omitting Metrius), 

 are — Anfarctonomus, Brachycselus and Migadops from Tierra del Fuego, 

 Monolohus and Rhytidognathus from Chili, Lissopterus from Falkland 

 Islands, and Heferodactylus from Auckland. 



Monolohus is remarkable in having the outer maxillary lobe of one 

 piece as in AmpMzoa. 



The tribe seems very naturally to lead from the Nebriini to the 

 Metriini. 



Migadops virescens Waterh., has considerable superficial resemblance 

 to Nehria virescens Horn. 



Tribe XL — Metriini. 



Antennfe moder.ate in length, straight, arising under a distinct frontal margin; 

 first four joints glabrous, the first joint stouter but not longer than the third, 5 — 11 

 subequal, pubescent. Eyes small, round, distant beneath from the buccal opening. 

 Head with a single setigerous puncture over the middle of each eye. Labrum 

 short, feebly bisinuate. Mandibles short, concave on the outer side and with a 

 distinct setigerous puncture. Mentum transverse broadest at middle, deeply eniar- 

 ginate and with a rather stout, bifid tooth, epilobes distinct, mental suture well 

 marked. Ligula broad, obtuse and bisetose at tip, the paraglossse distinct and 

 adherent in their entire length ; palpi rather stout, the last two joints of nearly 

 equal length, the second bisetose in front, the third broader to apex and truncate. 

 Maxillae with inner lobe rather short, distinctly hooked at tip and ciliate internally, 

 the outer lobe biarticulate and with equal joints; palpi rather stout, the terminal 

 joint nearly as long as the second, gradually broader to tip and obtuse. Thorax 

 transverse, a seta at point of greatest width another in front of the hind angles. 

 Bases of thorax and elytra in close apposition, scutellum indistinct. Elytra not 

 margined at base, moderately inflexed at the sides, the margin acute and entire. 

 Anterior coxal cavities closed behind, prosternum slightly prolonged and partly 

 covering the declivous and flat mesosternum. Femora moderately stout, the 

 anterior scarcely thicker. Anterior tibife obliquely grooved and emarginate near 

 the apex, both spurs terminal. Middle tibiae ciliate externally. Posterior coxae 

 separated by a rather broad triangular process of the abdomen. Tarsi moderate, 

 first joint longer than either of the three following, fourth not emarginate. 



The first joint of the anterior tarsus of the male is rather broadly dilated and 

 with the second densely spongy pubescent beneath. 



The metasternal side pieces of which no mention is made above are 

 sometimes simple, that is, with all trace of suture between the episternum 

 and epimeron obliterated or the suture may be more or less distinct and 

 the side pieces consequently double. 



The genus Metrius is the only one known to me wliich finds a place 

 in the present tribe. It is a very distinct type the affinities of which 



