172 • TERTIARY INSECTS OF NORTH AMERICA. 



3. Tribochrysa firmata. 



PI. 14, Figs. 6, 7, 10, 11. 



Two specimens are at hand, each in a pretty good state of preservation, 

 showing head and antennae, the body and wings, the latter generally some- 

 what confused by overlapping or folding. The head is rather small as com- 

 pared with the thorax, and well rounded, with moderately prominent eyes, 

 and antennje a fourth longer than the body ; the prothorax is also rather 

 slender, tapering considerably, and about as long as its posterior breadth. 

 The thorax is stout and the abdomen half as long again as the head and 

 thorax. The wings are about three times as long as broad, broadest in the 

 middle of the distal half, the costal margin pretty straight in the middle, 

 rather rapidly sloping basally, and very rapidly curving almost bending 

 downward apicall}^ the apical margin rounded, subacuminate, the apex 

 rather below the middle ; the inner margin is regularly and gently curved. 

 The subcostal vein joins the costal (not shown on plate) a little beyond the 

 middle of the distal half of the wing, and the costal area thus formed is occu- 

 pied by about a dozen or more straight cross-veins ; there are only eight or 

 nine subradial cells, and the cells in the series below this, while agreeing in 

 general character with those of T. inequalis, are less numerous than there, 

 there being only three elongated cells directly beneath the sector of the 

 radius and only five equiaxial cells in the same series beyond them. 



The two specimens show verj- little difference excepting in size, though 

 on that account they were at first presumed to be distinct. 



Length of body, 8.5-7.75""° ; of antenna?, 9.5-10.5"'" (in the larger 

 specimen no doubt imperfect) ; breadth of head, 1-0.85""° ; of thorax, 1.6- 

 1.5°""; length of fore wing, 11.25-9.75"""; breadth of same, 3.85-3.25"". 



Florissant. Two specimens, Nos. 670, 8792. 



Family PANORPIDvE Stephens. 



If the Liassic genus Orthophlebia is to be referred to this family, this 

 group must have been as abundant in Mesozoic times as now. Only a few 

 Tertiary species are, however, known, and those hitherto described have 

 unspotted wings like their ancestors of the secondary epoch. Three species 

 of Bittacus and one of Panorpa have been described from the European 



