THE CANADIAN ENTOMOLOGIST. 301 



them contained larvae at all, as they had been previously parasitized, 

 consequently we were unable to make much of a study of this species, 

 though their galls were quite common in certain localities. 



In the study of Eaura S. nodus we were unable to make a study of 

 the egg stage. Eggs are, however, undoubtedly laid by the adult female 

 about the time that the willows are leafing out in the spring. They are 

 deposited in a slit made in the bark by means of the little saw-like 

 ovipositor. As a result of the deposition of this egg within the twig, the 

 characteristic gall is formed where the larvae live throughout the winter 

 months, pupating in the spring. The adults make their escape by means 

 of the hole gnawed in gall by the larvae before they ceased feeding for the 

 winter. This, in general, is the life-history of the species. 



The following list of species occurring in some of the more 

 important genera of Colorado, though far from being complete, we trust 

 will aid in the further study of this interesting family. 



The references given do not in every case refer back to the 

 publication in which the original description occurred, but wherever 

 possible reference is made to some work commonly found in ordinary 

 libraries. 



The material at my disposal was that owned by the Entomological 



Dept. of the Colo. Ag. College. Those specimens which were seen and 



studied by me throughout the time of these investigations are marked 



-with a star; other species did not occur in the collection, but are reported 



as occurring in the State by other writers on the Tenthredinidae. 



Thanks are due Prof. Alex D. MacGillivray, of Cornell University, 

 for helping in the determination of some of the material, also to Prof. 

 C. P. Gillette, of the Colo. Ag. College, who kindly tendered the use of 

 his collection and library, and under whose direction the work was carried 

 out. 



*Cimbex americana. Leach, Proc. Ent. Soc. Phila., Vol. i, p. 201. 



j Trichiosoma triangulum, Kirby, Fauna fJor. Am., Vol. 4, p. 254. 



(. Trichiosoma aleutiana, Cress., Trans. Am. Ent. Soc, Vol. 8, p. r. 



( Zarsea americana, Trans. Am. Ent. Soc, Vol, 8, p. i. 



I (Abia americana, Cresson.) 

 *PIylotoma clavicornis. Fab., Trans. Am. Ent. Soc, Vol. r, p. 66. 

 *Hylotoma McLeayi, Leach, Trans. Am. Eut. Soc, Vol. r, p, 64. 

 *Hylotoma rubiginosa, Klug, Trans. Am. Ent. Soc, Vol. i, p. 72. 

 *Hylotoma scapularis, Klug, Trans. Am. Ent. Soc. Vol. i, p. 67. 



