308 GEO. H. HORN. 



MEGASTEKKUM Muls. 



Prosternum elevated, forming a somewhat hexagonal area, which 

 rather widely separates the anterior coxse, meeting the mesosternum 

 and having a notch in its posterior margin. Middle coxse widely 

 separated by a process formed partly of the metasternum and partly 

 by the mesosternum (PI. ix, fig. 10), the latter being in the form of 

 a broadly pentagonal plate, acute in front, the union between these 

 two sterna being very close, although with distinct suture. Meta- 

 sternal episternum very narrow, partly covered by the elytra; mes- 

 epimera covered. Epipleurse extremely narrow. Antei'ior tibise 

 deeply notched on the outer edge near the apex, all the tibise very 

 feebly spinulo-se on their outer side. Tibial spurs very inconspicuous 

 even on the front tibise. 



The characters, otherwise, are as in Cercyon, the palpi in no wise 

 differing, excepting that the last joint is very distintly longer than 

 the penultimate (PI. ix, fig. 26) and the pseudo-basal joint more 

 inflated than is usual in Cercyon. The tibise are broader and flatter 

 than in any of the genera to which it is related. 



The genus seems a perfectly valid one. It is represented in our 

 fauna by two species, which may be distinguished in the following 

 nianner : 



Head and thorax scarcely visibly punctate; elytnil strife fine, but distinct; the 

 intervals scarcely punctate, apex paler posticatuin. 



Head and thorax densely punctulate ; elytral striae obliterated, except at the 

 side, surface closely punctate puiictulatum. 



M. posticatnm Mann.— Oval, slightly narrower behind, convex, piceous 

 black, subopaque, sides of thorax and humeral spot indefinitely paler; elytra at 

 apex distinctly paler. Antennae rufo-testaceous, club piceous. palpi testaceous, 

 last joint piceous. Head smooth, shining, entirely piceous. Thorax indistinctly 

 paler at sides, these feebly arcuately narrowed from base to apex, basal marginal 

 Hue absent, a distinct ante-basal impression opposite the fourth stria, sometimes 

 indistinct or wanting, surface smooth, shining, a few .sparsely placed, very fine 

 punctures near the side. Elytra finely alutaceous, surface finely striate, striae 

 deeper near the apex, the punctures of the striae extremely indistinct at middle 

 of disc, but very obvious at sides and apex, intervals flat, not punctate. Body 

 beneath piceous, slightly shining, metasternal area smooth behind and at its 

 sides, punctate in front, the flanks of the metasternum coarsely punctate. Legs 

 rufo-piceous. Length .08 inch. ; 2 mm., a little more and less. 



The pale area at the apex of the elytra is always distinct, although 

 its limits are not sharply defined. The umbone may or may not 

 have the pale spot, in the former case the species resembles Cercyon 

 ocellatus. 



