DOKYCLTTS.— ATOMOSIA. 183 



of Amjpyw, Walker (1855), with Megapoda, Macq. (1834) ; and Arribalzaga, Anal. Soc. 

 Cient. Argent, xiii. (1882) pp. 185 et seq., has shown that Megapoda is the same as 

 Doryclus, Jaenn. The three genera united contain seven described species, some of 

 which are probably synonymous. The species being apparently variable in the intensity 

 of their colouring, it would be unsafe to establish these synonyms merely upon 

 descriptions. Doryclus, like some " Dasypogonina," has a strong hook at the end 

 front tibiae. 



The synonymy of M. cyaneiventris, Macq., is very probable, but not certain . 



PSEUDORUS. 



Pseudorus, Walker, Ins. Saunders. Dipt. p. 103, t. 4. f. 5 (1853). 



l. Pseudorus bicolor. 



Pseudorus bicolor, Bellardi, Saggio &c. ii. p. 11, t. 1. f. 20 \ 

 Hob. Mexico, Playa Vicente (Salle 1 )-, Guatemala, San Geronimo (Champion). 



I have compared a single specimen from Guatemala with Prof. Bellardi's type, and 

 believe that it belongs to the same species. The Guatemalan example has the thorax 

 dark brown above, chestnut-brown on the pleurae, and differs in this respect from 

 Bellardi's description; the wings are uniformly brown (except the subhyaline spot 

 within the cells) and do not have the hyali ne margin between the alula and the tip of 

 the sixth longitudinal vein, as indicated on the figure, but not mentioned in the 

 description. This is an accidental discoloration of one of the wings of the typical 

 specimen, as I ascertained in Turin. This species has only " two " submarginal cells, 

 and not " three," like P. pieeus. 



N.B.— Schiner says (Verh. z.-b. Ges. Wien, 1866, p. 653) that Pseudorus, although 

 figured with a closed marginal cell (he calls it subcostal cell), has in reality the marginal 

 cell open, and therefore bel ongs to the " Dasypogonina " and not to the " Laphrina." 

 He had two specimens showing this structure. This is singular, because Walker, 

 Westwood, Bellardi, and myself have had specimens of Pseudorus with a closed mar- 

 ginal cell. I can only suppose that in Dr. Schiner's specimens the edge of the wing 

 was somewhat folded, so as to conceal the narrow end of the marginal cell; in such a 

 case the second vein may appear as ending in the margin. 



ATOMOSIA. 



Atomosia, Macquart, Dipt. Exot. i. 2, p. 73 (1838) . 



The descriptions of Atomosice when read mostly leave the impression that they 

 represent one and the same species ; nevertheless, as soon as we attempt to determine 

 a specimen it often happens that hardly any of the descriptions will be found to fit it 

 ■exactly. I have two species before me, neither of which I can recognize among some 

 forty existing descriptions of North- and South-American Atomosice. 



