304 DIPTERA. 
Diplocentra simplex, Schiner, Dipt. Novara Reise, p. 237. 19 (Curtonotum) ; 
Gig].-Tos, loc. cit. (sep.) p. 36. no. 9. 
Tauromyia pachyneura, Gigl.-Tos, loc. cit. (sep.) p. 37. no. 6, tab. figg. 7, 8. 
The genus Diplocentra, though formerly regarded as belonging to the Helomyzine, 
is much better placed in the group Geomyzine (see Osten Sacken, Berl. ent. Zeitschr. 
xxvi. p. 243). 
As regards Zauromyia, Gigl.-Tos, the figure which the author has given of the 
wing shows evidently that the genus is likewise misplaced among the Helomyzine. 
The two inferior basal cells are almost rudimentary, a form of neuration quite foreign 
to this group. I presume that Tauromyia would be more naturally placed among’ the 
Geomyzine or some allied group. 
Group SCIOMYZIN A. 
In the broad front, with bristles on the posterior half only, and in the neuration of 
the wings, the Sciomyzine agree with the Helomyzine, but they differ from them in 
the absence of vibrisse. The face is somewhat retracted, without antennal furrows, 
and with the oral margin sharp; the antenne are rather long and projecting in some 
of the species; the legs are of moderate length (in Sepedon the hind femora are 
elongate) ; the tibiee have a preapical bristle, the middle pair with distinct spurs. 
I follow Loew (Monogr. of the Diptera of N. America, i. pp. 37, 103) in uniting 
the Tetanocerine with this group, these having been separated by Schiner (Fauna 
Austr., Dipt. ii.). 
Three genera are represented in the Mexican collections before me :— 
1. Antenne rather short, the third joint oval or circular, much longer than 
the second. . .. . . oe ~ . . + « Sciomyza. 
Antenne more or less prolonged, the second and third joints equally 
long, or the third shorter, this latter never circular . . . . . . 2. 
2. Front not excavated; eyes not prominent . . . . . . . . . . Yetanocera. 
Front excavated; eyes prominent . . . . . . . . «ss « + ©6Sepedon. 
SCIOMYZA. 
Sciomyza, Fallén, Sciomyz. Suec. p. 11 (1820). 
Of this genus I have to record five species from Mexico; one of them is identical 
with a European form and the others are new. 
1. Wings with dark markings. . . . . woe ee ee 
Wings without dark markings a 8. squalens the cross-veins are 
slightly infuscated) . . wee | 
2. Arista plumose; tips of the wings . broadly bordered with brown . infuscata, vy. d. Wulp. 
