THE CANADIAN ENTOMOLOGIST. 175 



4. The cell M3, or fifth posterior (cell in the forks of the cubitus, 

 according to the nomenclature proposed by me for the Nemestrinidae), is 

 present, and rather widely open at the apex. 



5. The cubital cell (Comst. and Needham) is also open at the apex. 

 It has been shown by Mr. C. W. Johnson (Ent. News, 1897, p. 118) 



that the presence of the fifth posterior cell is not a generic character in 

 this group, since in D. rufithorax it is present or absent, without even 

 specific difference. 



Hab. — D. revelata is from the Miocene shales of Florissant, Colorado, 

 at Station 14 (IV. P. Cockerell, 1907)- I submitted a drawing of this 

 species to Prof. A. L. Melander, and it is to him that I am indebted 

 for the suggestion that the species belongs to Dialysis. It is remarkable 

 for its large size, and some venational characters above indicated, but I 

 cannot find any sufficient reason for regarding it as another genus. The 

 characteristic flexure of R^ is exactly as in Dialysis. 



This is the first American fossil Leptid. Of Leptidae in the broad 

 sense (including Xylophagidae) numerous species have been described 

 from Baltic amber, but only one {Xylophagus pallidus, Heer.). from other 

 rocks, namely, from Aix. All of the European fossil Leptids are from the 

 Oligocene. 



NOTES ON TENTHREDINOIDEA, WITH DESCRIPTIONS OF 



NEW SPECIES. 



BY S. A. ROHWER, BOULDER, COLO. 



Paper I (Species from Colorado). ' 



The term middle fovea is used in these descriptions, and I expect to 

 use it from now on, for the fovea between the antennse. This is what Mr. 

 C. L. Marlatt (Rev. of the Nematinas of N. Am., Tech. Ser., No. 3. Dept. 

 of Agriculture) calls the antennal fovea. The term antenna! fovea in my 

 descriptions from now on will mean the fovea at the base of each antenna. 

 "Ocellar basin" is the basin in which the lower ocellus is placed. ''Middle 

 carina" is the carina that is sometimes found between the antennae. 



I am greatly indebted to Prof. C. P. Gillette for the loan of the 

 Saw-flies belonging to the Colorado Agricultural College. Also to Prof. 

 T. D. A. Cockerell for many valuable suggestions, and to Dr. A. D. 

 MacGillivray for permission to describe some Saw-flies which he had 

 named in manuscript. 



It is my plan to have a series of papers on Saw-flies, in some cases 

 giving notes and descriptions of new ones, and in others giving tables of 

 the species of America, north of Mexico. 



June, 1908 



