Wickham — New Fossil Coleoptera from Florissant. 127 



The holotype is in Peabody Museum of Yale University. 

 Cat. No. 4. 



Acilius Leach. 



A. florissantensis n. sp. The specimen shows an underside 

 in only fair preservation, the two hind legs in place and what 

 appears to be one of the patellate front tarsi, indicating that 

 the insect was a male. The species is about the size and shape 

 of our common A. semisulcatm but apparently with slightly 

 longer tibse and with the second abdominal segment somewhat 

 shorter in proportion to the third. Length 13 mm , width 9*25 mm . 



Station number 14. Collection number 257. Received from 

 Prof. Cockerell. Holotype in Peabody Museum of Yale 

 University. Cat. No. 5. 



No other species of this genus has been reported from the 

 Florissant shales, and while the specimen in hand is not suffi- 

 ciently perfect to show many truly specific features, it seems 

 worth while to characterize it as well as possible, since the 

 generic facies is quite well marked and so few fossil aquatic 

 adephagous beetles are known. The genus is represented in 

 North America by only three species, two of which are very 

 closely related. 



Philydrus Sol. 



P. scudderi n. sp. Almost regularly oblong-elliptical, 

 elongate, evenly and slightly narrowed at each end. Head 

 large, l'35 mm wide and -70 mm long, eyes not defined, antennge 

 and palpi lacking, except the pseudo-basal joint of one of the 

 latter which is too indistinct for study. Prothorax short, 

 broadest just perceptibly in front of the base, sides regularly 

 and slightly curved to the apex, front angles damaged, apical 

 margin roundly emarginate, base subtruncate at middle, 

 slightly sinuate each side, finely margined, hind angles appar- 

 ently slightly less than right and somewhat rounded. Sides 

 of elytra nearly straight to about the middle, thence gradually 

 regularly rounded to the apex. Sutural margin with very 

 fine bead. Legs not shown. Scutellum rather small. Length 

 5-25 mm , width 2-65 mm . 



The surface of this specimen shows a scabrous granulation 

 which is probably due, in part at least, to the decomposition 

 of the exoskeleton. It is, however, sufficiently well preserved 

 to show that the insect was black. On the sides of the 

 prothorax are some coarse punctures recalling the similar group 

 in Hydrobius fuseijpes. 



The specimen almost exactly resembles the description and 

 figure of Trojnsternus limitatus Scudder, also from the 

 Florissant field. I should have placed it there had not Dr. 



