NEUEOPTERA— PLANIPBNNIA— HEMEROIUNA. 163 



vein near the base and opposite the expansion of the costal margin, narrows 

 very gradually towards the apex, and by tlie deflection of the subcostal vein 

 next the tip is cai-ried to the very angulation at the apex, filled throughout 

 with very numerous, oblique, straight, and simple cross-veins. The radius 

 runs in exceedingly close proximity to the subcosta until the margin begins 

 to curve decidedly downward, when it unites with it. I have not been able 

 to detect certainly any basal or other cross-vein between the two, though 

 there are in some specimens slight indications of what may be one near the 

 origin of the main sector ; they certainly do not occur elsewhere. The main 

 sector originates from the radius near the base of the wing, runs near to and 

 parallel with it to the apex, and is connected with it by many (eight or nine) 

 cross-veins ; from it arise eight or nine parallel, oblique, and nearly straight 

 sectors, making in all about a dozen series of equal oblique interspaces in 

 the wing, broken in the apical half of the wing by a couple of series of 

 gradate veiidets, the outer not very far removed from the posterior margin 

 and subparallel to it, finally merging in one of the basal branches of the 

 radius, and from which spring the marginal veinlets whicli are usually deli- 

 cately forked at the very border ; the inner row is parallel to the outer and 

 about as far from it as it is from the margin. Within this the interspaces 

 are broken by a dozen or more irregularly scattered rather distant cross- 

 veins, much asinOsm. pictusof the Prussian amber, but very diff'erent in- 

 deed from the living types of the genus, as already stated under the genus. 

 The margins of the wings are sparsely furnished with delicate hairs, and 

 similar hairs may be seen on some of the veins, especially near the margins, 

 but at great distances, or farther apart tlian tlie length of the hairs. The 

 hind wing does not differ essentiall}' from the front wing, excepting in the 

 width of the costal area. 



Length of body, 9.75"""; of antenna?, 10"""; of front wing, 15.35°""; 

 breadth of same, 5.35""". 



Florissant. Three specimens, Nos. 8839, 13012 and 13537, 13538 and 

 14168. 



BOTHROMICROMUS Scudder. 



Bolhromicromus Scudd., Rep. Geol. Surv. Can., 1876-77, 46-2 (1878). 



This genus agrees with Micromus in lacking the recurrent vein above 

 the costal vein next the base of the front wing, and differs from it in the very 

 wide expansion of the costal area at this point and in the possession of 



