WICKHAM: fossil ELATERIDAE of FLORISSANT. 511 



sides, (judging by the better preserved one), gently and regularly 

 rounding, base and apex subequal or the latter a little narrower, front 

 angles obtuse, not at all prominent, hind angles moderately acute, a 

 little divergent and distinctly carinate. Thoracic punctuation rather 

 shallow and obscure, close and only fairly fine, surface strongly hairy. 

 Scutellum pointed at apex. Elytra moderately tapering to apex, not 

 striate and very obscurely punctate but hairy like the thorax. Length, 

 from front of head to elytral tip, 7.10 mm. ; of elytron, 4.75 mm. 



Described from one specimen. 



Type — No. 2,751 M. C. Z. Florissant, Colo. (No. 12,485 S. H. 

 Scudder Coll.). 



Looks a good deal like E. florissantcnsis but is smaller and has non- 

 striate elytra. Probably it does not belong to Elater in the modern 

 sense. 



Megapenthes primaevus, sp. nov. 



Plate 4, fig. 2. 



Form rather elongate. Head finely but extremely densely and 

 quite deeply punctured, somewhat less strongly upon the vertex 

 than upon the front. Antennae reaching well beyond the base of 

 the prothorax, heavier than in most of the fossil Elateridae but not 

 very strongly serrate, only the middle joints well defined. Prothorax 

 narrower at apex than at base, approximately equal in length and 

 breadth, surface finely and closely punctured though not quite so 

 strongly as the head, sides but little arcuate, front angles short, 

 hind ones not very long, a little divergent and distinctly carinate. 

 Scutellum oblong. Elytra conjointly rounded apically, finely striate, 

 strial punctures roimded, mostly separated by about their own diam- 

 eters or a little more, interspaces flat, wide, finely and not very closely 

 punctate, the punctures distinctly smaller than those of the striae. 

 Underside not shown. Length, 8.90 mm.; of elytron, 5.60 mm.; 

 of prothorax, 2.35 mm. 



Described from one specimen. 



Type.— No. 2,750 M. C. Z. Florissant, Colo. (No. 10,859 S. H. 

 Scudder Coll.). With it are associated two others, in the Museum of 

 the University of Colorado, one with counterpart (No. 226 and 249). 

 The only one with definite record is from Station 13B, collected 

 by S. A. Rohwer. 



As seen under magnification, the general effect is much like that of 



