CHERMES OF MAINE CONIFERS. 305 



Technique. At the time these species were studied, live mate- 

 rial was available both for the pupae and winged forms. The 

 general form of the individual was sketched first from live 

 material and such structures as could then be ascertained were 

 indicated. Details were studied and drawings completed from 

 balsam mounts. Live specimens in some cases were mounted 

 directly in the balsam and a few desirable results obtained 

 for immediate use. In each case, however, a large series of 

 mounts was carefully made for study, drawings, and photo- 

 micrographs. Total mounts were most satisfactory after the 

 general method (modified according to size, readiness of pene- 

 tration of the fluids, etc.) indicated as follows: 

 Killed in hot 98 per cent alcohol, 

 One hour in 80 per cent alcohol, 

 One-half hour in 98 per cent alcohol, 

 Ten minutes in 100 per cent alcohol, 

 Ten minutes in tolu. 



Antennal details were taken from head mounts. Wings were 

 each species mounted separately. Where total mounts did 

 not bring out clearly the wax gland areas of both thorax and 

 abdomen, severed specimens were prepared to facilitate the 

 more rapid and thorough clearing. 



This detailed account of the method of preparation is given 

 in order that the character of the material used may be recorded. 

 Certain groups of wax pores, for instance, were not rendered 

 visible in one or two species except in dissected specimens 

 and in most, a large series was necessary to settle the number 

 definitely. Some variation occurs in the size and arrangement 

 of the groups of wax pores, but individuals figured and des- 

 cribed represent the typical wax pore areas as they were seen. 

 As the wax pores are often difficult to see the most convenient 

 specific characters will be found in the wing and antennal char- 

 acters which are distinctive and within slightly varying limits 

 were constant, for the extended collection in this locality at 

 least. 



WING VEIN NOMENCLATURE. 



For the nomenclature of the wing veins used here the reader 

 is referred to H ontologies of the Wing Veins of the Aphididae, 

 Psyllidae, Aleurodidae, and Coccidae, Annals of the Entomo- 

 logical Society of America, June 1909. 



