664 STATE BOARD OF AGRICULTURE. 



it is thought that all the soda is elimiuated, after which they pass into 

 weak alcohol and from that to strong alcohol. Some of the specimens 

 are placed for a short time in 95% alcohol saturated with magenta, 

 which aids greatly in bringing out derm markings. Finally they are 

 placed without rinsing in chloroform and allowed to stay there for an 

 hour or more, to be finally mounted under pressure in raw balsam and 

 dried with gentle heat. 



Photo-micrographs of the natural browns and yellows are made with 

 the aid of a blue color screen (Wratten No. 45) and those stained 

 magenta, usually come out better when a green screen is used. (Wrat- 

 ten No. 58). 



The works of Messrs. Wm. B. Thro, J. G. Sanders, E. Ernest Green 

 and Robert Newstead of the more recent writers have been used freely 

 in the attempt to place the different forms. Thanks are due to Dr. G. T>. 

 Shafer, Palo Alto, California, to Prof. C. W. Woodworth of the Uni- 

 versity of California, to Professor J. G. Sanders of the Penn. Depart- 

 ment of Agriculture, to Mr. Huber Hilton, Supervisor in the Forestry 

 service, to Mr. F. G. Kilp of Trout Lake, Wis., and to Mr. E, O. Essig 

 of the University of California for coccid material, also to Prof. Glenn 

 Herrick of Cornell University, for securing the loan of type material 

 of L. ottusum of Thro, for study. 



All the forms have been included under the name Lecanium, because 

 the various sub-genera proposed seem to grade into one another too 

 closely to render profitable any attempt to separate them until some 

 one revises the genus as ,a whole. It is believed that a study of the 

 American species of this genus wdll result in a marked reduction in 

 the number of species. 



It is felt by the writers that this bulletin is from necessity incomplete, 

 for the reason that further collecting will undoubtedly yield more 

 species, therefore the writing of a key has been deferred until a later 

 date. 



LECANiuM (Toumcyella) corrugatum Thro. 



A medium sized L^canium on Pine. The females often crowded 

 together on the twigs, while the males occupy the leaves. Male scales 

 rather slender and delicate, having the usual ridges. Females reaching 

 1/5 inch in length ; shape somewhat globular unless distorted by crowd- 

 ing, which tends to make them more elevated and irregular in outline. 

 Color brown; surface wrinkled. 



When boiled in caustic soda, the liquor is stained a red-brown. In 

 region of anal-plates there are scattered a number of circular gland- 

 pores and all over the derm are irregular clear spots each with a dark 

 dot inside. Antennae of three joints, vestigial in type. 



Anal-plates triangular, with angles rather abrupt. There is one 

 fringe seta on each side. Dr. Thro* describes two. No doubt indi- 

 viduals may be found with two. There are four sub-apical setae on 

 ventral suriface, and three apical setae on dorsal surface, on each side. 

 There are also four or five hypopygial setae on each side extending in 

 a curve from the fringe seta forward to near the median line. The 

 spiracular setae are i)laced three in a group, the middle one being 



♦(Bui. 209 CorneU University Exp. Sta.) 



