92 TERTIARY COLEOPTERA OF NORTH AMERICA. 



the American species, and is double tlieir size. The general form is uni- 

 formly oval excepting for the 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 striae, as 

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

 the legs appear to be very different from Cytilus. The tibiae have their 

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

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

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

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

 and is somewhat mutilated behind. 



Length, 8 mm.; breadth, 4.5 mm. 



Florissant, Colorado; one specimen. No. 7740. 



Cytilus dormiscens. 



Cytihts dormiscens ScudcL, Tert. rhynch. Col. U. S., pi. 1, fig. 1 (1892). 



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

 the rather large eye; antennae hardly longer than the head, the terminal 

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

 Thorax apparently tapering but little, and so having an appearance A^ery 

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

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

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

 with faint signs of delicately impressed striae. Femora rather stout, tibiae 

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

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

 smooth. 



Length, 5.5 mm.; breadth, 3 mm. 



The short antenna?, hardly agree with Cytilus. 



Florissant, Colorado; one specimen, Nos. 8068 and 8193. 



BYRRHUS lAxmL 



A north temperate genus with tolerably numerous s^iecies, 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 



