288 Miss G. Ricardo on the Pangoninz 
agree must be sunk in Sélvius (see Schiner, Reise der 
Novara; Loew, Dipt. Stidafrik.), the species becoming 
Silvius vulpecula. 
Rhinomyza, Wiedem. (Dipt. Exot. i. p. 29, 1821), is 
looked upon by Loew as a doubtful genus, the only character 
which divides it from Silvius being the greater deepening of 
the face in the centre; he leaves it standing for the present, 
adding a new species and suggesting that Silvius denticornis, 
Wiedem., should belong to it. 
Erodiorhynchus, Macq. (Dipt. Exot. i. p. 110, 1838), 
formed for L. eristaloides, Macq., is a synonym of Rhinomyza 
edentula, Wiedem., according to Loew, whose remarks on 
this and the above genus do not agree with those of Schiner 
(‘ Reise der Novara’); but Loew is followed here, as being 
probably most correct, Schiner’s remarks on Rhinomyza 
being clearly wrong. The latter makes a new species, 
Erodiorhynchus pusillus, which should perhaps belong to 
Silvius, or more probably to Rhinomyza, though he does not 
mention the face as being concave in the centre, as it should 
be, if belonging to Rhinomyza. 
Macquart’s description of the genus is most inadequate 
and seems to give no characters which would distinguish it 
from Silvius or Rhinomyza ; it is therefore not maintained in 
this paper, but merged again in Rhinomyza for the present. 
Rondani (Archiv. Canestr. ii. p. 85, 1863) subdivides 
Silvius, creating two subgenera, and taking the hairiness or 
nakedness of the eyes and the closed or open posterior cell 
as characters on which to found them, viz.: Veprius for 
those species of Silvius with hairy eyes, leaving those with 
naked eyes in Silvius. It does not seem worth while to 
retain this subgenus. Hsenbeckia he establishes for two 
species from Brazil and Chili, which have the first posterior 
cell of the wings closed, a characteristic peculiar to them 
alone, I believe, so that for the present this subgenus may 
be allowed to stand. 
Gastroxides, Saunders, and Pronopes, Loew, were each 
formed for one species. 
Rondani established the genus Nemorius (Prodrome Dipt. 
Ital. i. p. 171, 1856) for Chrysops vitripennis, Meig., a 
species with clear wings, and differmg somewhat from the 
other European species, as Loew remarks in Dipt. Stidafrik. 
p- 16: see also Verh. zool.-bot. Gesell. Wien, viii. p. 616 
(1858), where he regards it as unnecessary to separate it 
from Chrysops; I have therefore not included the genus 
Nemorius in the following table of genera :— 
