164 DESCRIPTIONS OF NEW SPECIES. 



slightly thickened external!}'. The generic characters are suffi- 

 ciently detailed in the work cited above. I observe no sexual 

 differences, except that the antennas of the male are more than 

 half the length of the body, and the distance between the eyes is 

 not greater than their diameter ; while in the female the antennas 

 are shorter and the eyes more distant.* 



XAMTHOCHROA Schmidt. 

 412. X. trinotata. Valde elongata, fusca, breviter pubescens, 

 capite nitido modice punctato, flavo-testaceo, vitta longitudinali, labro, 

 palpis maxillaribus, mandibularum apice, palporum labialium articulo 

 ultimo antennisque nigris ; tborace campanulato, latitudine longiore, 

 lateribus sinuatis, antice rotundatis, disco nitido modice punctato, antice 

 postice et utrinque versus latera impresso, flavo-testaceo, lateribus 

 vittaque dorsali lata nigris ; elytris dense punctatis, lineis utrinque 

 duabus elevatis versus apicem obliteratis, tertia externa obsoleta, quar- 

 taque submarginali distincta, limbo suturali marginalique testaceo ; 

 subtus fusca, propectore, coxis anticis et mediis, femorum tibiarumque 

 basi testaceis. Long. '50. 



One specimen, Louisiana ; Mr. Ulke. Easily distinguished 

 from X. lateralis by the larger size, the less finely punctured 

 thorax, which is marked with a broad black dorsal vitta. 



COPIDBTA Leg. 



Corpus elongatum graeile. Caput latitudine longius, antice sensim 



angustatum ; oculi subtiliter granulati, modice transversi, late distantes, 



antice vix sinuati ; antenna? filiformes, utriusque sexus 11-articulata?, 



articulo 2ndo brevi, 3io sequenti aequali, llmo (maris) superne sinuato, 



* The analytical table of genera of Oedemeridae, on p. 258 of Class. Coll. 

 N. America, is quite defective ; the following may be substituted as show- 

 ing the relations of the genera after Microtomes : — 



Antennse not embraced by the eyes ; middle coxa? contiguous ; 

 Body stout ; tarsi with the joints 4, 3, 2, spongy beneath. Ditylus. 

 Body slender ; 



Anterior tibia? with one terminal spur ; 



Eyes feebly emarginate. Nacerdes. 



Eyes deeply emarginate. Xanthociiroa. 



Anterior tibia? with two terminal spurs ; 

 Ungues simple or obsoletely toothed ; 



Mandibles bifid at tip. Copidita. 



Mandibles acute at tip. Oxacis. 



Ungues strongly toothed at base ; 



Mandibles acute at tip. Probosca. 



Mandibles bifid at tip. Asclera. 



