AMERICAN COLEOPTERA. 117 



Mystropomus is now placed at the head of the tribe Ozaenini by 

 Chaudoir, but the reasons why it should not be placed there are very 

 many. In the discussion of that tribe will be found the reasons for 

 removing it from association with the true Carabin^e. The mesosternal 

 epimera do not reach the middle cosal cavities as one can prove by 

 softening the specimens in a solution of caustic potassa when the sutures 

 become evident and mere plications of the surface obliterated. 



In Mi/stropomus however we have a structure of body resembling 

 very closely Metrius not only in the inflexed sides of the elytra but 

 their general appearance. The epimera and episterna of both segments 

 are likewise constructed on a similar plan and the posterior coxae sepa- 

 rated. On comparing the form of head and antennae and even the 

 mouth parts we have a striking analogy with Metrius. I am disposed 

 to consider Mi/stropomus^ the closest ally in every respect with Metrms 

 and with Migadops an intermediate link toward the Nebriini. 



It is remarkable that this genus should occur in Australia. Lacordaire 

 (Atlas pi. 5, fig. 5K gives an illustration of the species which might 

 however be improved. 



Tribe XIII.— Promecognathini. 

 Antennse slightly geniculate, arising under a slight frontal margin, first four 

 joints glabrous, the first much larger and stouter than the others, 5 — 11 slightly 

 compressed and finely pubescent. Eyes small slightly oval and distant from the 

 buccal opening. Head with two supra-orbital setse, neck slightly broader behind 

 the eyes. Labrum short, bisinuate. Mandibles elongate, arcuate and acute at tip 

 and decussating, not toothed within. M'entura short, broad, broadly emarginate 

 and with a broad short tooth, epilobes narrow but distinct, mental suture distinct. 

 Gula deeply transversely impressed so that the mentura is inserted at a right angle 

 to the peduncle. Ligula moderately prominent narrower and free at tip, truncate, 

 with two setae, paraglossse long, rather slender and ciliate within at the tip. 

 Maxillae with inner lobe slender and long, obtuse at tip, densely ciliate within, 

 outer lobe biarticulate the terminal joint much shorter. Maxillary palpi moder- 

 ately long, the second joint equal to the next two together, terminal joint broader 

 at tip truncate and twice the length of the third. Labial palpi with the last two 

 joints about equal in length, the terminal broader at tip and truncate, the pre- 

 ceding bisetose in front. Thorax narrowed at base, sides narrowly inflexed, lateral 

 margin distinct, a setigerous puncture near the hind angle and three at the side 

 in front. Body pedunculate, scutellum invisible. Elytra not margined at base, 

 lateral margin distinct and entire, sides narrowly inflexed. Anterior coxal cavities 

 closed behind, prosternum not prolonged, mesosternum declivous. Metasternal 

 epimera indistinct. Femora stout, the anterior more strongly clavate. Anterior 

 tibire gradually broader to tip, smooth externally, deeply emarginate internally, 

 the inner spur remote from the tip. Posterior coxae separated by a triangular 

 process of the abdomen which meets the metasternum. Tarsi moderate, the 

 posterior longer, first joint moderately long, fourth slightly emarginate. Tarsi 

 similar in the sexes. 



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