92 TERTIARY COLEOPTERA OF NORTH AMERICA. 



i 



the American species, and is double their size. The general t'urin is uni- 

 formlv oval excepting for tlie slight prominence of the head, which may be 

 entirely due to the state of preservation; the head is about half the width 

 of the body. The elytra, are furnished with rather deep and sharp stria j , as 

 in existing species of Cytilus, but are distinctly though finely punctate, and 

 the leg's appear to be very different from Cytilus. The tibia- have their 

 opposite sides similarly and very slightly arcuate, and in the middle legs 

 are as broad as the femora, though not more than two-thirds their width in 

 the hind legs. The hind tarsi are as long as the hind tibia-, the last joint 

 and claws quite as in the living Cytili. The specimen shows no antenna} 

 and is somewhat mutilated behind. 



Length, 8 mm.; breadth, 4.5 mm. 



Florissant, Colorado; one specimen, No. 7740. 



CYTILUS DORMISCENS. 



Cytihm dwmiscens Seudd., Tcrt. rhynch. Col. V. S.. pi. 1. fig. 1 (1802). 



Head very finely and profusely punctate, with some fine wrinkles above 

 the rather large eye; antenna' hardly longer than the head, the terminal 

 joints a third broader than the basal, of about equal length and breadth. 

 Thorax apparently tapering but little, and so having an appearance very 

 unlike a byrrhid, but this is apparently due to distortion in preservation; it 

 is much broader than long, truncate at both extremities, linelv, profusely, 

 and uniformly punctate. Elytra similarly but not so heavily punctate, 

 with faint signs of delicately impressed stria-. Femora rather stout, tibia? 

 moderately so, tapering- at either end, with a few delicate spines. Under 

 suiiace of thorax punctured like the elytra, of abdomen nearly or quite 

 smooth. 



Length, 5.5 nun.: breadth, .'3 mm. 



The short antenna- hardly agree with ('vtilus. 



Florissant, Colorado; one specimen, Nos. SOUS and S1S3. 



BYKUIIUS Linnc. 



A north temperate genus with tolerably numerous species, of which 

 about half a dozen occur in North America. In the Old World the genus 

 is recognized in the English Pleistocene, and three species have been found 



