﻿150 THE ENTOMOLOGIST. 



So, to make things pleasant all round, tills individual would have 

 to be furnished with a name also. 



In his ' Code of Varietal Nomenclature,' Mr. Cockerell (I. c.) 

 proposes terms expressive of certain kinds of variation common 

 to many species of Lepidoptera, and the adaptation of one or 

 other of these suitable to the occasion would, in the majority of 

 cases, convey as clear an idea of the form referred to as an 

 extended description could do. There is, too, this distinct ad- 

 vantage, that whereas the one refers to a phase of variation, the 

 other singles out a particular individual, and elevates it to the 

 dignity of a type, a distinction which in some cases it certainly 

 does not deserve* It should be remembered that these third names 

 are really epitomised descriptions ; therefore if we wish to inform 

 a friend, or the entomological public at large, that we have taken 

 some specimens of A. cursoria in which all the markings are 

 absent, we can do so shortly, by writing A. cursoria deleta. In 

 the case of specimens received from foreign localities, with the 

 fauna of which we are not quite familiar, it is not only permissible, 

 but highly desirable, as a check to synonymy, that names should 

 be given to specimens showing any well-defined aberration. 

 These examples might certainly prove, on further examination, 

 to be distinct species ; but then no harm would be done, as all 

 that would be necessary would be to state the fact, and their 

 names would go with them in their promotion. At all times, 

 well defined local forms or races of a known species should be 

 named ; and, when it can be done, it would be well if such 

 names were framed, with reference to habitat, or, perhaps, better 

 still, to some striking feature exhibited by the form. 



CRITICAL NOTES ON DIPTERA. 



By G. H. Vekball, F.E.S. 



As to the five species introduced as new to Britain by Mr. 

 Brunetti (Entom. 122), Psilocephala ardea, F., is quite properly 

 noticed; the species introduced by B. Cooke as Thereva fusci- 

 pennis, Mg., in Ent. Mo. Mag. xv. 19 was really Psilocephala 

 ardea, F., as I have since ascertained from, some of the original 

 specimens in Dr. P. B. Mason's collection. Consequently 

 Thereva fuscipennis, Mg., should be erased from my list and 

 Psilocephala ardea, F., substituted. Lasiops semicinerea, W., 

 has nothing to do with the genus Lasiops, and is in my list as a 

 Hyetodesia ; it is very common in the North, while I have taken 

 it as far South as Sussex and Devonshire. I have seventeen 

 localities for it. Leria ruficauda, Zett., is probably correct ; I 



* Possibly this is so with Heliophobus Ivispidus var. obsoletus (Entom. xxii. 137). 



