78 DIPTEEA. 



tion of the genus. In his generic definition the statement "pulvilli present, but 

 generally small and narrow " is not correct. 



Eondani attempted a subdivision of the genus, based on differences in the venation ; 

 in the absence of specimens, however, he established his new genera merely upon the 

 figures of the wings as given in Macquart's ' Dipteres Exotiques ;' the rest of the 

 organization he therefore entirely ignored*. As might be expected, the result of this 

 attempt is far from happy (comp. Eondani, 'Archiv. per la Zool.' iii. 1, Modena, 1863). 



Argyrospila, Eond. (Prodr. i. p. 162, and Archivio, I. c), is based solely upon the 

 first posterior cell being closed — a character of secondary importance, which occurs in 

 species that would find themselves far apart in a natural grouping; and this is the 

 case with the very species enumerated by Eondani as belonging to his new genus : — 

 E. pandora (Europe), E. limbipennis, Macq. (Mexico), E. olivieri and E. lugubris, Macq. 

 (Arabia). The last two I have never seen (nor Prof. Eondani either); in E.jacchus 

 (syn. pandora) and its close relatives E. cleomene &c. all passages occur between a 

 closed and petiolate first posterior cell and an open one. It would be as unnatural to 

 place those species in different genera on that ground as to form a separate genus for 

 E. pandora and the totally different E. limbipennis, merely because both have that 

 secondary character in common. Even as a specific character the open or closed first 

 posterior cell is sometimes but of little value. Of E. cleomene, Egger, this author says, 

 " the first posterior cell is open in most, but closed in some, specimens " (Verh. zool.-bot. 

 Ges. Wien, 1859, p. 398). The same is said by Loew about some other species of the 

 same relationship ; compare Loew, Beschr. eur. Dip. i. p. 212. (In the species allied to 

 E. limbipennis, Macq., this character is more constant.) The genus Argyrospila, Eond., 

 can, therefore, not be maintained. 



The genus Hyperalonia was introduced by Eondani for certain species with four 

 submarginal cells, due to the presence of a supernumerary cross-vein within the third 

 submarginal. In examining the species of this group which I have before me I 

 observe that they all have the ungues on the posterior legs without tooth at the base, 

 which tooth characterizes the true Exoprosopce. I find the same character in the 

 Asiatic Exoprosopce with four submarginal cells which I am able to compare (Doryca, 

 Boisd., (Enomaus, Eond.; no Exoprosopce with four submarginal cells are known from 

 the Cape yet). These two characters, taken in conjunction, may justify the establish- 

 ment of this group, which I have adopted below. 



Heteralonia was introduced by Eondani for Exoprosopa oculata, Macq. Dipt. Ex. ii. 1, 

 p. 45, from Senegal (not occulta, as Eondani has it), merely on the strength of the figure 

 of the wing in Macquart, which shows a supernumerary cross-vein bisecting the second 

 submarginal cell. (Eondani, in consequence of an erroneous interpretation, describes 

 this venation — the fourth vein joining the third, or, in his own terminology, " vena 



* A similar proceeding by Eondani in the family Micropezidse has been noticed by me in the Berl. ent. Zeit. 

 1882, p. 199. 



