THE CANADIAN ENTOMOLOaiST 161 



Pdratypcs 3 J^'s. Aweme, Man. (Aug. 12th, 15th, 18th) ( N. Criddle) in Cana- 

 dian National Collection and Collection Barnes. 

 ' The species resembles considerably a miniature agitatcUus Clem, but the 

 white stripe is narrower and has no tooth on lower margin ; the coloration shows 

 less of the ochreous shades found in this latter species. A specimen from South 

 Park, Colo., (Oslar) in the Barnes Collection appears to belong to this species. 

 Worn specimens tend to show a general diffusion of the white areas. 



A METHOD OF MAKING PHOTOGRAPHIC PRINTS OF 



INSECT WINGS. 



BY R. P. GORHAM, 

 Assistant Entomologist, Entomological Branch, Ottawa. 



In some work with Diptera it was found desirable to obtain a series of 

 photographs of wing venation in a number of different families. A very con- 

 venient, inexpensive and rapid method of making these was found, and, as it 

 seems possible that it may be of use to others, it is herewith described. In brief. 

 it consists of using the insect wing itself as a negative and making an enlarged 

 print. 



In making the prints the first step is to mount one. or a number of 

 wings, between two sheets of glass so they may be held flat. Glass miscroscope 

 slides are found to be of a desirable size. For quick work the wing or wings 

 are placed in position on one slide and another similar slide placed over them 

 and held in place by rubber bands. For a permanent mount to be kept for 

 future use, the wing is mounted in balsam. The slide is then placed in a 

 printing frame at the back of a camera and the latter set up in the window 

 of a dark room in the ordinary way for enlarging. The image is projected on 

 a white screen, which is moved toward or away from the camera until the 

 desired size of wing is obtained. Then the shutter is closed and a sheet of 

 bromide paper pinned on the screen and exposed in the usual way to the light 

 rays passing through the wing and camera lens. With very bright sunlight 

 out-of-doors and using enameled paper, one-half minute to one and one-half 

 minutes has been found sufficient time with the smallest of shutter openings. 

 The' time will vary with the intensity of the light and the density of the wing. 



For ordinary use a print showing a wing length of three inches is found 

 sufficiently large. All details can be clearly seen in a print of that size, and four 

 such prints can be made on one sheet of 5 in. x 7 in. paper. Prints can be made 

 of any desired size up to the limit of the paper available. In the case of the 

 Culicidffi large prints show the scales on the wing veins clearly. 



The method seems well adapted for the study of wing venation in those 

 orders of insects having hyaline wings, as the photo-print is more accurate than 

 an ordinary drawing. All parts are enlarged to such size that they can be 

 distinctly seen without the use of a lens, and the exact position of picture spots 

 and shadings of the membrane is also shown. Another advantage is that a 

 number of wings of dift'erent species can be printed together at one time on one 

 sheet of paper for comparison by the eye or by measure — all being enlarged the 

 same number of times. 



A few test prints made from lepidopterous wings mounted in Xylol- 



