AHT. 18 JASSID GENUS TYPHLOCYBA McATEE 5 



lifrhts interfere add more glycerine to keep the specimen completely 

 submerged. For drawing it is desirable sometimes to hold the parts 

 in a fixed position. This can be done ^Yith glycerine jelly. Slightly 

 warming the jelly fits it for reception of the specimen which can 

 be manipulated into the desired position with needles (warmed if 

 necessary). The jelly will gradually set and when it seems assured 

 rhat the specimen will retain its position, the slide can be laid on 

 some cool object to complete the hardening process. To avoid losing 

 the connection between the treated hypopygium and the insect from 

 which it was removed, the wa-iter transfers them from the slide to a 

 drop of shellac on the same card point on which the insect is 

 mounted. The glycerine and shellac seem to form a persistently 

 viscous combination, from which the specimen can be removed at will 

 for further examination, and which is transparent enough to permit 

 seeing details sufficiently in many cases so that removal is unneces- 

 sary. How long this desirable consistency of the mounting medium 

 will persist is unknown, but if a solvent is needed, alcohol which 

 can not injure the specimen will serve the purpose. 



TECHNIQUE FOR DRAAVINGS AND REPRODUCTIONS THEREOF 



Whether made by the aid of the binocular or the monocular micro- 

 scope, drawings are scaled b}^ a grid-ruled micrometer and drawn 

 on graph or profile paper. The divisions on both the micrometer 

 and the paper being on a decimal system, proportions of the draw- 

 ing take care of themselves. Details also are traced easily and 

 quickly even b}' one not especially proficient in drawing. Use pro- 

 file paper with faint blue ruling; inlc in the drawing with rather 

 heavy lines and have about half of the reduction ultimately desired 

 made by photography. The blue lines are thus eliminated, the 

 drawing standing out well on a nearly white background. By this 

 process the operations of tracing and redrawing the figures are 

 eliminated.^ Another way in which the same economy of effort may 

 be had is to make the drawing directly on tracing paper held station- 

 ary over a sheet of profile paper. 



NOMENCLATURE OF THE GENITALIA 



The nomenclature for the parts of the genitalia are partly adapted 

 from those used by Lawson " and Brittain ^ and partly improvised. 



* Using the technique described In this and in the preceding section, the writer is al)le 

 to clear and describe a hypopygium and make all drawings required for one species in an 

 hour, and to do all work necessary to idontitlcation of a previously known species In from 

 10 to 15 minutes. 



"Kans. Univ. Sci. Bull., vol. 12, 1920, pp. 44-52. 



' Proc. Acadian Ent. Soc, No. 8, 1922, pp. 62-06. 



