164 TERTIARY INSECTS OF XORTB AMERICA. 



numerous sectors. In these respects it agrees with Drepanepteryx, but the 

 wing is not falcate, and notwithstanding the wide expanse of the costal area 

 the recurrent nervule is wanting, all the veinlets of this area arising next 

 the base, as elsewhere, from the siibcosta. The wing is shaped much as in 

 Megalomus, to which, indeed, it is closely allied, being broad at the base, 

 very gradually increasing in width apicall}', the extremity rounded, with 

 no abrupt emargination or falcation, but with the inner angle strongly ex- 

 cised. At the base the costal area is nearly as broad as the remainder of the 

 wing ; the costal veinlets are all furcate and apparently connected, much as 

 in Drepanepteryx, by a single line of inosculating veinlets, dividing the area 

 in two nearly equal longitudinal halves. The costa and subcosta run side 

 by side in the closest proximity, but are apparently separated to the apex. 

 Sectors extremely numerous, with a single complete series of gradate vein- 

 lets in the middle of the wing, and another, apparently crossing only the 

 lower half of the wing, more than half-way between this and the outer 

 margin ; veins and margins very shortly ciliated. 



The genus also seems peculiar in the structure of the maxillary palpi, 

 the basal joint of which is half as broad again as long ; the second and third 

 joints subequal, moniliform ; the fourth a^Dparently only half as broad as 

 the previous, but of equal length, and the terminal again slenderer, but 

 twice as long, being conical, pointed, and unarmed, while the others are 

 furnished on the apical half with scattered setse. Antennte submoniliform, 

 the joints near the base of equal length and breadth, the basal joint double 

 the width of the others ; no hairs can be seen upon the antennal joints. 



BOTHROMICEOMUS LACHLANI. 



PI. 2, Figs. 7-10. 



Bothromicromus lachlani Scudd., Rep. Geol. Surv. Cau., 1876-'77, 462-463 (1878). 



One front wing and a part of the head with its appendages are pre- 

 served on No. 36, with a pale, brownish tint to the wing, while the reverse, 

 on No. 37, is wholly colorless. The only parts of the head preserved are 

 one eye and a portion of the other, indicated by a broad, black, annular 

 ring; also a few of the basal joints of the antennae, and both maxillary 

 palpi, crossing each other and detached from the head. The wing is strongly 

 expanded at the extreme costal base ; beyond this the costal border is 

 straight, with a scarcely perceptible emargination nearly to the tip. The 



