206 TERTIARY INSECTS OF NORTE AMERICA. 



length, in tlie male as long as the abdomen beyond the wing tips, somewhat 

 depressed, with the basal third straight, its basal half with straight and 

 parallel sides, its ajjical half narrowing on the inner side, the whole inner 

 margin pinched and perhaps a little crenulated, but not toothed nor beaded; 

 the distal two-thirds very gently and slightly arcuate, scarcely tapering, the 

 curve increasing slightl}' toward the bluntlv rounded tip. In the female 

 they are a little shorter, much slenderer and apparently cylindrical through- 

 out, scarcely attingent at the base, with no pinching of the inner edge at 

 the base, and very regularl)^ and gently tapering to a more delicate but 

 still bluntly rounded point ; the arcuate curve is if anything a little stronger, 

 and commences from the base, though the straight basal portion of the male 

 is sometimes indicated by the origin of the arcuation (on the outer edge) at 

 a little remove from the base. Pygidium of the male (not shown in the 

 figures) triangular, longer than broad, half as long as the greatest breadth 

 of the forceps, the apex broadly, bluntly rounded; in the female as long as 

 broad and as the base of the forceps, more or less slightly truncate and 

 rounded at apex. 



Length of body, excluding forceps, <? 19""°, $ 18-19""°; breadth of 

 abdomen, 3.5-4"=": length of front and middle femora, 2.5";"; tibia-, l.TS™"; 

 tarsi, 1.5°'"; of hind femora, 2.8""; tibia, 2.3™"'; of forceps, ,? 8.5"", 2 6.5"""; 

 breadth of same at base, S 1.4"", ? 0.7""; in middle, S 1"", 2 0.4"". 



This is the most interesting of the Florissant species on account of its 

 great size and the long and simple forceps. It is twice as large as any 

 living species of Forficula. 



Florissant. Eight specimens, Nos. 11740, 13544 and 13545, 13547 {S), 

 2855 and 3567, 3832 and 5532, 5438, 8022, 11209 ($). 



2. Labiduromma bokmansi. 



PL 16, Fig. 1 ( ^ ). 



In the two specimens referred to this species the head and pronotum 

 are badly preserved, but so far as can be seen appear to be much as in L. 

 avia in relation to each other and the combined tegmina ; the prothorax is, 

 however, certainly larger, thouah slightly, than the head, and the antennal 

 joints at a short distance from the head are three or four times as long as 

 broad. The tegmina are large with broadly rounded posterior edges, and 

 the body with straight parallel sides ; the last segment is as broad apically 



