12 ILLINOIS BIOLOGICAL MONOGRAPHS |330 



in checking up materials in other collections and in comparing the de- 

 scriptions of Young with his own material. This collection is designated 

 by the letter C. 



The Maine collection consists of about 200 species, many of which were 

 bred and identified by Dr. MacGillivray. The collection belongs to the 

 Maine Agricultural Experiment Station and all the specimens were in 

 excellent condition. They were collected by Dr. MacGillivray with the 

 assistance of Mr. Earl Shaw during the summer of 1913 in the vicinity of 

 Orono, Maine. This collection together with the collecting and breeding 

 records were placed in the writer's hands, and they proved to be indis- 

 pensable to the present study. The collection is designated by the letter 

 M. 



The MacGillivray collection consists of about thirty-five species 

 collected and identified by Dr. MacGillivray, together with larvae of 

 some unidentified species. The specimens came from Ithaca, N. Y., 

 Orono, Me., Onekama, Mich., Urbana, 111., and a few other localities. 

 This collection is designated by the letter G. 



The Yuasa collection consists of about two hundred and thirty species 

 including 98 bred species. A majority of the specimens were collected by 

 the writer at Ithaca, N. Y., during the summers of 1917 and 1918. Some 

 species were collected at Urbana, 111., and others came from different 

 parts of the United States and Canada thru the generosity of various 

 entomologists. This collection contains also the cocoons of practically all 

 the bred cocoon-making species and eggs and pupae of a limited number of 

 species. This collection is designated by the letter Y. 



Besides the four collections just mentioned, a number of rare speci- 

 mens were generously loaned to me by several people, as subsequently 

 acknowledged, and were of great value in the preparation of this paper. 



Identification. — All bred species in the Maine, MacGillivray and 

 Yuasa collections were identified by Dr. MacGillivray. Some of the 

 specimens in the Cornell collection bore labels, and when the larvae agreed 

 satisfactorily with the published descriptions the identifications were 

 accepted. In only a few cases has identification depended solely on 

 published descriptions of larvae. 



Terminology and Nomenclature. — For the description of the external 

 anatomy of the head and mouth-parts of the larvae the terms used in my 

 paper (1920) dealing with the generalized insects have been used. Other 

 terms, some new, are used in part II. Taxonomic names have been 

 adopted from Rohwer (1911) and MacGillivray (1906). 



Bibliography. — Works on taxonomic units are omitted altogether. A 

 complete bibliography of the Nearctic Tenthredinoidea was not under- 

 taken owing to space limitations, but the most important literature on 

 the subject is listed, as also that cited in the text. 



