Readio: Ovipositors of Cicadp:llid^. 223 



characters are constant within (he species has been proven by ex- 

 amining a wide range of in(h\-i(hials within the species and finding 

 that the \-ariation was negligible. C'onst'ciuently, for the taxononiic 

 part of this paper, valve II is used exclusively. 



The technique used in mounting valve II for study is simple. The 

 tip of the abdomen bearing the oN'ipositor is broken off from the 

 dried specimen, soaked in ten i:>er cent caustic potash for twenty- 

 four hours, washed in water for a few minutes, valve II and other de- 

 sired parts dissected out under a binocular microscope, dehydrated 

 in ninety-five per cent alcohol for five minutes, cleared in xylol for 

 five minutes, and mounted in balsam on a microscope slide. It is 

 well to give the slide and the specimen from which the slide w^as 

 made a corresponding number, so that any necessary checks may 

 be made. This method gives a permanent mount, which may be 

 studied at the convenience of the worker. 



Several methods of figuring the ovipositor were used. The first 

 was that of drawing the desired valve free-hand with the aid of a 

 micrometer eyepiece divided into squares, which correspond to 

 squares on the drawing paper. This is a satisfactory method, but 

 somew^hat more laborious than the methods later used. The second 

 was to draw with the aid of the camera lucida. The particular 

 equipment available did not give satisfactory results at all times, 

 but there is no doubt but what this method could be used with 

 satisfaction. The greatest degree of success was obtained by the 

 use of the Edinger drawing apparatus. This apparatus projects the 

 desired image upon the drawing paper, and the figuring consists only 

 of tracing in the image. Photography w'as tried and found to be a 

 very successful means of reproducing the desired image. A camera 

 fitted for ordinary scientific work was used. It w^as turned to a ver- 

 tical position and a lens board fitted with a black, light-proof sleeve 

 was inserted in the front lens-board holder. The sleeve was lowered 

 over the ocular of a compound microscope, and focusing for desired 

 size and definition of image accomplished by a combination of 

 microscope and camera adjustments. Various substitutions in ob- 

 jectives and oculars were necessary to meet all conditions. Illumi- 

 nation was furnished by an ordinary substage light, and exposures 

 were made by the switching off and on of this lamp. Undoubtedly 

 much better results could be obtained with the aid of special photo- 

 micrographic equipment. 



Descriptions of the ovipositors of the generji and species of the 

 various subfamilies follow: 



