24 TERTIARY t'OLKOPTKRA OF NORTH AMERICA. 



or simple i'lvtr:i. It is of about the s;uno si/c as /'. jnunjH'Ilt/i : the head is 

 smooth with a similar, luit sometimes inconspicuous, transverse impressed 

 line between the antenna': the thorax is squarely truncate anteriorly, with 

 slightly projecting front angles, sides broadly, rather regularly and some- 

 what strongly rounded, so that the thorax is as broad posteriorly as ante- 

 riorly and fullv half as broad again as long. Some specimens show a 

 tendency to subangulate sides, and the slight median impressed line is 

 scarcely noticeable in any (not given in the figure): the surface is eiitirely 

 smooth. The elytra are smooth and flat but for the regular and not deep 

 stria\ which show no punctuation and leave the interstitial spaces without 

 convexity; there is a moderately long sutural stria connecting with the first 

 longitudinal stria. 



Length of body, 1 fi mm.; of elytra, 9 to 9.5 mm.: width of one, 3 to 



. * 



3.5 mm. 



Florissant, Colorado; six specimens, Nos. 259, 5:21 and 4C40, 1781, 

 3105, 5131, and No. 1.557 of the Princeton College collection. 



I give this species the name of (.'. D. Walcott, Director of the United 

 States Geological Survey. 



KYAUTHRUS LeO.mte. 



The following is the only known fossil species of this genus, a consid- 

 erable north temperate group with about a dozen North American species. 



EVAKTHRUS TENEBRICUS Sp. 11OV. 



PI. T. tig. 8. 



Of this only the head is preserved, but this is so different from any- 

 thin"- else which has been found fossil that it merits mention. It is of 



D 



about the size of I'lritrtliriix //I'l/rii/ns I laid., and is placed in this genus on 

 account of the brevity of the last joint of the labial palpus. The head is 

 subquadrate, about as long as broad, slightly narrower in front than behind, 

 with two transverse lines, one in front of and the other behind the antenna', 

 the formei the transverse impressed line of the upper surface, the latter the 

 base of the labium seen through the head : the eyes are rather large, but 

 not at all prominent: the mandibles stout and strongly curved: the maxil- 

 lary and labial palpi unusually stout, the joints of the former subequal, not 

 more than t \\ice as loii^- as broad: of the latter, the ultimate very much 



