248 T. D. A. COCKERELL. 



The venation ha.s been considered very aberrant, but in a former 

 paper (Am. Jn. Sci., April, 1908) I have regarded it as primitive, 

 and have seen in the nervures which bound the second posterior cell 

 the true branches of the cubitus. This view differs from that of 

 Comstock and Needham, and, if sustained, requires a partial modi- 

 fication of their nomenclature. In the accompanying figures I have 

 indicated the veins as I understand them. The following synopsis 

 includes all the known North American species, recent and fossil. 



Synopsis of North American Nemestrinid^. 



A. — Proboscis long, projecting anteriorly; subf. Nemestrininie (Miocene in N. 

 America; living in Asia). 



PAL.K9IBOL.lJS Scudder. 

 Palemholus Scudder, Bull. U. S. Geol. and Geog. Surv. Terr., iv (1878), p. 526. 

 PaZm&oZos Scudder, in Zittel. Hanbd., i (ii), p. 808 (1885), fig. 1076; Eastman's 



Edition, i, p. 688, fig. 1467. 

 Palomholus [err. typ.] Handlirsch, Foss. Insekten, vii (1907), p. 1009. 



Related to Nemestrina (species from Turkestan compared), but 

 without any cross nervure from the radial sector to the base of the 

 fork of the media. 



Paleinbolus florigerus Scudder, 1. c. 



Miocene shales, Florissant, Colorado. Type in Museum of Com- 

 parative Zoology, Harvard University. 



I am greatly indebted to Mr. A. P. Morse for examining, at my 

 request, Scudder's type of Palembolus. He compared it carefully 

 with the figure given in Zittel's work, and found it in the main as 

 there represented, but differing in slight details. "The wings are 

 narrower proportionately than represented. The dhtal half of wing 

 on right side of figure is more nearly correct, and tlie basal half of 

 wing on left side." There was no evidence ivhatever of any third 

 radio ■riiedlal cross-nervure ; in lacking this nervure tlie genus agrees 

 with the Jurassic Prohirmoneura on the one hand, and tlie living 

 Trichophthalma albibasis (as figured by Handlirsch) on the other. 

 There was some indication of "seam- veins" in the right wing (but 

 not in the left), especially one forming a broadly triangular pseudo- 

 cell, with its apex at the point of branching of the media. Mr. 

 Henshaw also examined this structure, and agreed with Mr. Morse 

 that it was not a genuine vein ; indeed, from its position, it could 

 hardly be one. Whether we liave here some indication of the retic- 



