FOSSIL COLEOPTERA 33 



Eyes transverse, moderate in size. Antenna? slightly inerassate towards the 

 tips, eleven-jointed, first joint rather large, second small, third a little longer 

 than the fourth, the remaining joints more distinctly broadened, forming 

 the club. Prothorax arcuately emarginate anteriorly, basal margin sinuate, 

 sides arcuately tapering to apex but somewhat imperfectly preserved. As 

 near as can be judged from the condition of the specimen the pronotum 

 was about two and one-fourth times as wide as long. Elytra about three 

 times as long as the prothorax and rather broad, overlapping along the 

 suture in the specimen so that their conjoint width is not properly shown. 

 In places there are signs of striae marked with rows of very fine punctures 

 as shown in the figure. Legs wanting. Length, 8.00 mm. Width across 

 both elytra, 4.3.5 mm. 



Station number 17. One paired specimen, collector not specified. The 

 type is in the Museum of the University of Colorado. 



This insect must have been much like our recent P. ruficorne 

 in build and probably had a similar but finer sculpture. The 

 antenna? are comparatively somewhat broader at base in the fos- 

 sil and the third joint is less distinctly elongate, but neither of 

 these characters have more than specific value. The genus is well 

 represented in the United States and Central America by species 

 of varying form, size and color. One other, P. hethunei, is known 

 from the Florissant shales, and is readily distinguished from P. 

 antiquormn by being much larger and of more elongate form. 



MORDELLISTENA Costa. '■ 



M. FLORISSAXTEXSIS n. sp. (Plate II, Fig. 16.) Preserved in profile. 

 Head large. Prothorax as long as high, the dorsum slightly arched. Elytra 

 two and a half times as long as the prothorax and nearly four times as 

 long as wide, scarcely tapering to the tips which are blunt and rounded. 

 Abdomen, as preserved, projecting far beyond the elytral apices, the ex- 

 treme end pointed but without a distinct style. Length from front of head 

 to apex of abdomen, 3.3.5 mm. 



Station number 13. Collected by S. A. Eohwer. The type and only 

 known specimen is in the Museum of the University of Colorado. 



Easily distinguished from Mordella lapidicola, the only Flor- 

 issant species of the family yet described, by the much smaller 

 size of the present insect. I place it in Mordellistena, rather than 

 in MordcUa. partly because of its minuteness, since the tibiae and 

 tarsi are not well enough preserved for the exact demonstration 

 of the oblique ridges characterizing the former genus, in case of 

 their existence. There seems, however, to be two short ridges on 



