198 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



chance that some previous work will turn up later in which 

 the type species is already indicated. 



A work of this character is satisfactory in proportion to its 

 thoroughness and the impartiality with which it has been 

 carried out. It can readily be seen that, in the case of the 

 same species being included in two different genera, one of 

 these genera can be invalidated by simply indicating such 

 species as the type of both genera. In such case the result, 

 instead of being that most to be desired, to save the largest 

 number of generic names for possible later subdivision, is to 

 invalidate as many of them as possible. This has actually 

 been done. Thus the genus Lepiselaga Macquart was founded 

 on a single species ( Tabanus lepidutus Wiedemauu) ; the genus 

 Hadrus Perty had five species originally included, among 

 them the same Tabanus lepidotus, and Mr. Coquillett fixes 

 upon this as the type species. It is true that the recent modi- 

 fications of the international code of zoological nomenclature 

 countenance this procedure, but most systematists will con- 

 sider it very objectionable. In the case of the Schizophora, 

 which are systematically in a very unsettled state, such a 

 course is nothing less than mischievous. It is therefore unfor- 

 tunate that types once validly fixed must hold. 



A matter on which very few workers will agree with Mr. 

 Coquillett is the recognition of the old generic names of Meigen, 

 published in 1800 without any species associated. Mr. Coquil- 

 lett has indicated types for these genera, whereas the code 

 prescribes that the type must be one of the originally included 

 species. This, too, is upheld by the International Commis- 

 sion's recent rulings, to which Mr. Coquillett is a strong ad- 

 herent. In the opinion of the reviewer the recognition of 

 such genera contradicts the generally accepted position that a 

 genus must be founded upon an actual object; in other words, 

 on a species. 



In addition to its confessed aim the work has another pur- 

 pose. It is no less than an attempt to decide the validity of 

 all the genera. It is clearly beyond the powers of anyone to 

 determine the status of all the genera in the Diptera. To 

 place genera in the synonymy without discussion of the points 

 at issue is not only unscientific but unfair. These decisions 

 of Mr. Coquillett, however, have no binding effect. 



The activity of the reviewer in the field of systematic dip- 

 terology has been too limited to enter into detailed discussion 

 of the work. However, a few obvious omissions and errors 

 can be pointed out by way of indicating the danger of relying 



