INSECUTOR INSCITI^ MENSTRUUS 65 



lower submerged portion and that longitudinal area of egg free 

 from investing capsule to escape and wriggle freely to the 

 depth of the water. The egg remains doubled upon itself with 

 a wide gaping aperture along its longitudinal aspect, the margins 

 of which are thrown into folds, and an irregularly torn vent at 

 its submerged base (Plate III, fig. 5). 



THE MOSQUITOES OF THE PALAEARCTIC AND 

 NEARCTIC REGIONS 



(Diptera, Culicidce) 



By HARRISON G. DYAR 



In the November, 1921, number of the "Bulletin of Ento- 

 mological Research," Mr. F. W. Edwards gives a valuable 

 review of our present knowledge of the palaearctic mosquitoes. 

 The region included is far too extensive for a direct comparison 

 with the North American fauna, as it extends to northern 

 Africa and in the east to Japan ; but by selecting those species 

 inhabiting the region in Europe that corresponds to our Cana- 

 dian region, the comparison becomes instructive. It appears 

 that the palaearctic and nearctic faunae were continuous at a 

 comparatively recent date. Some of the more stable species 

 are identical, others are racial, others representative, and the 

 rest are derivatives. There are no species proper to the fauna 

 which have a diverse origin. 



In some details it seems necessary to dissent from Mr. Ed- 

 wards's conclusions. Exactly what degree of difference consti- 

 tutes a species and what a geographical race or variety is more 

 or less a matter of individual opinion. I think that where con- 

 stant differences appear in any stage that specific rank is indi- 

 cated, and treat the forms accordingly in the following. 



Genus Anopheles Meigen 



The only species occurring in our Canadian fauna is occi- 

 dentalis D. & K. Mr. Edwards considers this the same as the 

 European maciiUpcnnis Meig. He has considered the differen- 



