On the Dipterous Subfamily Ditomyine. 431 
vein which extends from costa to second vein, a large one 
over apex of second vein, and a much less distinct one at 
apex of third vein. Calyptrz white. Halteres yellow. 
Eyes separated by a little over width across posterior 
ocelli ; arista pubescent; parafacial at base of antennz as 
wide as third antennal segment, narrowed below. Post- 
humeral bristle duplicated; three or four pairs of weak 
acrostichals in front of suture ; prealar very long. Abdomen 
depressed ; hypopygium small. Fore tibia with one antero- 
dorsal and one posterior median bristle, apical posterior 
bristle long, straight; mid-tibia with one antero-dorsal, two 
postero-dorsal, and two posterior bristles ; hind femur with a 
complete series of irregular antero-ventral bristles and some 
widely spaced postero-veutral bristles ; hind tibia with two 
postero-dorsal, one antero-ventral, and three antero-dorsal 
bristles, the posterior surface bare. Costal thorn minute ; 
wing pointed, third vein ending almost in tip. 
Length 4-5 mm. 
Type and paratype, La Plata City, Argentina, 10. vi. 1896 
(O. Thomas). 
This species bears a striking resemblance to Hylemyia 
punctipennis, Wiedemann, but may be separated from it by 
the shorter-haired arista, larger single spot on outer cross- 
vein, presence of only two postero-dorsal hind tibial bristles, 
and absence of posterior setulz on hind tibia. 
L.—A Note on the Dipterous Subfamily Ditomyine, with 
Descriptions of new Recent and Fossil Forms. By 
F. W. Epwarps. 
(Published by permission of the Trustees of the British Museum.) 
In a recently published paper* Keilin has discussed in 
detail the larval morphology of three European genera 
formerly included in the Mycetophilide, subfamily Myceto- 
biine, and has given very strongreasons for considering that 
Mycetobia is closely related to Anisopus (Lhyphus), while 
Ditomyia and Symmerus are widely different and quite un- 
related either to Mycetobia or any other Mycetophilide ; 
he has even proposed the new family-name Ditomyiide for 
these two genera, considering them to be more closely 
related to Bibionide than to Mycetophilide. 
In regard to Mycetobia, I have been able to confirm + 
* Ann. & Mag. Nat. Hist. (9) iii. pp. 33-42, pls. ii.—v. (Jan. 1919). 
+ Ibid. (8) xvii. pp. 108-116 (Jan. 1916). 
