Some more objections. 



to that of some " culex " mosquitoes, appears to show 

 that generic distinctions cannot be based upon scale 

 structure alone. 



2. The classification is based in great part on the shape, and 



not upon the presence or absence, of scales. Scales of 

 various shapes are present on different parts of the 

 thorax, abdomen, and especially the wings of "anopheles," 

 and it is a matter of great difficulty to decide in some 

 instances what form of scale predominates ; nor does 

 Mr. Theobald give us any indication of what portion of a 

 wing, for example, should be examined to decide this point. 



3. The terms " lanceolate," " long and narrow," " true scales," 



&c., are not sufficiently definite to permit of such scales 

 being easily distinguished from one another except 

 perhaps by Mr. Theobald himself. It is obvious that 

 the distinction between " hair-like curved scales " and 

 " narrow curved scales " is not great, and also that it 

 would be difficult to decide whether the abdomen is 

 " hairy," or whether it is covered with " hair-like scales" 

 which apparently resemble hairs so closely that they 

 cannot be termed " true scales." As regards the wing 

 again it would certainly be difficult to decide whether 

 most of the scales were " lanceolate " or whether they 

 were " mostly long and narrow " especially as the part 

 of the wing to be examined is not stated, but on this 

 decision alone depends the distinction between the 

 genera Anopheles and Myzcmyia. 



4. One of the objects of classification is to simplify the identi- 



fication of species, but the new classification does not aid 

 this in any way. In practice, it will be found much 

 easier to determine the specific name of any specimen of 

 " anopheles " than its generic name according to the 

 new system. 



5. Species which differ widely in their habits and patho- 



logical significance (e. g., rossi and culicifacies) are placed 

 in the same genus, while those which are similar in 

 these important respects (e. g., listoni and jeyporiensis} 

 are placed in different genera. 



20] 



