208 TERTIARY INSECTS OF NORTH AMERICA. 



sometimes the fourth segment on some specimens with faint indications of 

 lateral plications; last segment a little longer tlian the preceding, narx-owing 

 slightly posteriorly with rounded posterior angles ; hind margin of male 

 strongly angulated, as shown in Fig. 6, of female straiglit Avith minute trian- 

 gular pygidium. Forceps broad, flattened, stout, long, and nearly straight, 

 as long as the foui or five terminal segments, the basal two-fifths straight, 

 equal, tlie attingent inner edges thickened slighth', the next two-fifths nar- 

 rower, particularly by the excision of the inner edge, tapering, nearly 

 straight, the apical fifth still narrower, more tapering, bent slightly inward 

 and bluntly rounded at tip (s), very broad and flattened, straight, scarcely 

 tapering before the middle and then but slightly, tiie apex apparently twice 

 as broad as in the male and bluntly rounded (?\ 



Length of body, excluding forceps, S 16.5-17.5°=", 5 18™"; breadthof 

 head, 1.8"™; of tegmina, 3.5"""; of abdomen, 4.3""'; length of middle and 

 hind femora, 3"™; of fore femora, 1.7""; middle and hind tibiae, 2.2""; 

 ore tibitB, 1.2"" ; length of forceps, S 5.5""', 2 4.5""? ; breadth of same at 

 base, c? 1.05"", ? 1.3™"'; at tip, S 0.35"'". 



This species differs from the two preceding species by its shorter, 

 broader, and straighter forceps. One of the specimens (Fig. 2) was taken 

 by me in the original insect beds described by Dr. A. C. Peale. 



Florissant. Six specimens, Nos. 395, 3705,6317 (<?), 8049, 13001 (?). 

 No. 1.615 ((?), Princeton Collection. 



4. Labiduromma commixtum. 



PI. 16, Figs. 10, 17 ( 9 ). 



Head moderately small, Avell rounded, the posterior border a little trun- 

 cate. Pronotum considerably smaller than the head, subquadrate, of equal 

 length and breadth. Tegmina together considerably broader than the head 

 and nearly double the breadth of the pronotum ; each of the tegmina about 

 twice as long as broad, and the coriaceous portion of the wings extending 

 beyond them for a distance equal to half their length. Legs slender and 

 rather long. Abdomen slightly expanding, so as to be broadest in the middle 

 and broader tlian the tegmina, yet witli subparallel sides ; last segment a 

 little longer than the others, slightly broader in front than behind, the pcs- 

 tei'ior margin broadly rounded. Pygidium very large, being at base one- 

 third the width of the terminal segment, subtriangular but strongly rounded. 



