KAHL: NEW SPECIES OF SYRPHIDA. I41 
upper half of the former yellow (forming a transverse band), 
the latter in one specimen with an inconspicuous post-ocellar 
dot yellow (Macquart’s female has: ‘‘ Face jaune, sans bande 
noire. Front fauve; une tache noire a l’insertion des antennes 
et une petite protubérance noire au milieu”); scutellum yellow 
with brown base and a black spot on each lower angle (Macq., 
’ 
‘*écusson fauve’’), coxe, trochanters, femora (except the rufous 
knees) and the tibia (except the pale almost white basal half 
of the middle and hind and the basal fourth of the front ones) 
blackish brown; tarsi dark brown, pulvilli rufous (Macquart’s 
diagnose, ‘‘ Pedibus rufis’’). 
M, aphritinus Thomson, Kongliga Svenska fregatten Eugenies 
Resa omkring Jorden, Vetenskap!]. Iakttagelser, Diptera, p. 
491; 1869.—-Sidney (Australia), male. 
M. bellula Williston, Biologia Centrali-Americana, Dipt., Vol. III, 
Pst); tab. 1, fig. 1, ta, tb; 1891.—-Mexico, male. 
M. dimidiata Giglio-Tos, Diagnosi di nuove specie di Ditteri, VI. 
Sirfidi del Messico, in Boll. Mus. Zool. Anat. comp. R. Univ. 
di Torino, Vol. VII, no 123, 1892;—Id., Ditteri del Messico, 
Parte I, p. 33, tav. I, fig. 9, ga (Estr. dalle Memorie della 
Reale Accademia delle Scienze di Torino, Serie II, Tom. 
XLII. 1892.)—Tuxpango, female. This species is distin 
guished by the extraordinary, arcuate impression of the face. 
Ceria Willistoni, n. sp. 
Syn. Certa stgnifera Williston (non Loew), Synops. N. Am. Syrph., p. 262. 
Black with yellow markings; face with a large, sagittate, black 
Spot; antenniferous process of front almost obsolete; second joint 
of antenne about half as long as the third; last section of third 
longitudinal vein appendiculate and slightly angulate; second ab- 
dominal segment much contracted at base; fifth segment black, not 
at all pollinose. Length about 13.5 mm., length of wing 9.5 mm. 
Female. Shining, except the upper three-fourths of front, the 
black of mesonotum and the sternum, which are opaque; the black 
of abdomen a little shining only. ‘The perpendicular face, which 
has a very slight impression at the middle and below a hardly 
noticeable tubercle, yellow, in the middle with a large black sagit- 
tate spot, the broadly rounded apex of which rests on the oral 
Margin and its base narrowly connected with the broad black field 
below the antennae; this black field extends transversely to the 
orbit of the eye, separating the yellow of the face from a small 
yellow somewhat triangular spot situated at the orbit of the eye 
