WICKHAM: FOSSIL ELATERIDAE OF FLORISSANT. 528 
eleventh much longer than the tenth. Eyes not strongly convex. 
Prothorax a little broader than long, slightly narrower at apex than 
at base, front angles acute, sides gently and almost regularly arcuate, 
faintly sinuate in front of the hind angles which are acute and feebly 
divergent. The thoracic apex seems hardly emarginate, the base is 
notched in front of the scutellum and sinuate each side. Punctuation 
of pronotum close, deep, and rather coarse over the entire surface, 
the punctures everywhere separated by much less than their own 
diameters and but slightly less crowded along the median line than 
at sides, each with a central mark which looks as if it may have been 
the point of insertion of a hair or scale. Scutellum oval, much longer 
than wide, coarsely punctured. Elytra moderately tapering, not 
pointed at apices, confusedly but in general evenly punctured except 
that the punctures become somewhat more sparse posteriorly where 
they are separated by spaces about equal to or a little more than their 
own diameters. Each puncture carried a moderately long, curved 
dark hair, giving a somewhat shaggy appearance to the surface. 
Underside of body well preserved, showing the following features: — 
prothoracic flanks finely and densely punctured, prosternum, includ- 
ing the spine, more coarsely and deeply; lobe strong, rounded; 
sutures double, nearly straight, excavate anteriorly; meso- and 
metasternal areas similarly but in general less closely punctate, coxal 
plates narrow, little dilated externally, with a rounded lobe over the 
insertion of the thighs; abdominal punctuation rather fine but deep, 
closer externally but everywhere well separated. Legs not well 
displayed. Length, from front of head to tip of abdomen, excluding 
sex organ, 14.25 mm.; of prothorax, along median line, 3.35 mm.; 
of elytron, 9.00 mm.; of antenna, 3.65 mm.; width of prothorax, 
3.75 mm. 
Described from one specimen, with counterpart. 
Type—In the collection of H. F. Wickham. Wilson Ranch, 
Florissant, Colo. 
This is probably the finest and best preserved specimen I have 
seen among the Elateridae of the Florissant shales. The aspect is 
much like that of a Ludius or of a Megapenthes, like the recent west- 
ern North American M. aterrimus, but the form of the coxal plates 
indicates a position with the Corymbitini. The punctuation does 
not agree with that of any species of the group known to me and 
serves at once to differentiate it from all the Florissant fossil Elateridae 
of similar size. The antenna and sex organ are omitted (Plate 4, 
fig. 7) but the former is shown (Plate 4, fig. 8). 
