12 ENTOMOLOGICAL NEWS. [Jan., '13 



tion to that of the nadel, but not too close to the end. Refer- 

 ence to the figure will more fully explain this. This finishes 

 the actual mounting and by the use of the gauge, the slip can 

 be run up on the large pin to the given distance, thus making 

 uniform mounts. Finally, by the application of a drop of di- 

 luted white shellac at the junction of the slip and the large 

 pin, a very rigid mount is obtained, leaving the nadel free to 

 turn, as is often necessary to present certain aspects for ex- 

 amination. With relaxed specimens, after the same have 

 been dried, a blotter should be used instead of the bristol 

 board so that the point of the nadel can protrude further 

 through the thorax. This will insure a more solid mount, as 

 the body juices are not present to cement the specimen to the 

 pin. 



These mounts have a very neat, uniform appearance, and 

 the method, although seemingly rather complicated and 

 lengthy, is very simple, and after a little practice becomes very 

 easy, and one can mount as rapidly as with any other double- 

 mounting method. This method insures as perfect specimens 

 as is possible, and gives access to any surface for examination 

 with a compound microscope, and although it has been used 

 before, I do not see many examples in the collections I have 

 examined. It should be used by all who mount small Diptera, 

 and when one collects by sweeping, the material is often gath- 

 ered in such large numbers that one needs a rapid and safe 

 method for mounting the same. 



Notes on the Phototropism of Certain Mosquitoes 



(Dipt.). 



By HARRY B. WEISS, New Brunswick, N. J. 



The different species of mosquitoes exhibit quite dissimilar 

 reactions with regard to their avoidance of and attraction to 

 sunlight. Some are apparently both equally positively and neg- 



