406 TERTIARY INSECTS OF NORTH AMERICA. 



times as broad as long, the posterior lobe more than one-third of the whole, 

 tapering pretty regularly and very considerably from base to apex, which 

 is not more than two-thirds as long as the base. Femora stout and large. 

 Hemelytra with the coriuni extending a little beyond the middle of the 

 abdomen. 



A single species is found at Florissant. 



Prolyg^us inundatus. 

 PI. 27, Fig. 13. 



Head very faintly and finely punctate, oblique sides of the thorax 

 gently convex, front margin of tliorax marginate and broadly and slightly 

 emarginate ; surface distinctly, rather distantly and uniformly punctate. 

 Corium of hemelytra rather heavily punctate in series which are more or 

 less longitudinal. 



Length, 5.5"" ; breadth of thorax, 1.85°"" ; abdomen, 2.6°"". 



Florissant. One specimen. No. 6299. 



19. NECROCHROMUS gen. nov. (venpo?, xpt^M^t). 



Body very regularly oval, the broader end posterior, the abdomen being 

 very full, laterally expanded beyond the costal margins of the closed heme- 

 lytra, the whole body less than twice as long as broad. Head with the 

 moderately large eyes just as broad as the apex of the thorax, almost as long 

 as broad, being strongly and angularly produced in front of the eyes, which 

 are situated at or close to the base. Ocelli small, situated close to the e3'es 

 on aline with their posterior margin; antennae as long as head, thorax, and 

 scutellum, the first joint not or but slightly surpassing the front, the other 

 joints subequal, the fourth slightly the longest, the third shortest, the last 

 two gently incrassated. Thorax transverse, broadest at base, tapering rather 

 or very rapidly, scarcely longer than the head, the sides convex, the obscure 

 posterior lobe rather less than one-fourth of the whole. Legs, or at least 

 the femora, pretty stout. Hemelytra with the corium surpassing the middle 

 of the abdomen to a greater or less degree. 



Three species are known, all from Florissant. 



Table of the species of Necrochronma. 



Thorax about twice as broad as long. 



Apex of tliorax more than tlirre-fourths as long as base; corium of hemelytra short. 1. N. cockn'elH. 



Apex of rhorax hardly more tUiii liiilf as loug as b ise; coriuia of hemelytra long 2. N'. lahatiia. 



Thorax about half as broad again as long 3. X. aaxificua. 



