segment slightly longer than broad. 
Mesonotum. 3+1 strong dc, acr sparse, 
in 2 rows. 
Wing. Length in male 2.5 mm, 2d 
costal section very short, little 
longer than 4th. 
Color. Frons , gena, and face orange 
yellow; orbit slightly darkened to 
lower ors , pale below; entire hind- 
margin of eye black; 1st antennal 
segment yellowish, 2d and 3d black, 
palpus black; mesonotum and scutellum 
matt gray, side of thorax similar, 
apart from narrow yellow upper margin 
of mesopleuron; legs black, knees 
narrowly yellowish; abdomen entirely 
gray; squama pale gray, margin and 
fringe black. 
Male genitalia. Aedeagus (figs. 1190, 
1191) long, dist iphallus divided, with 
characteristic curvature; main ventral 
sclerites joining distal end of basal 
sclerites strong, a weak, largely mem- 
branous lobe situated more basally, 
left basal sclerite short, half length 
of right; sperm pump small, blade 
slightly asymmetrical. 
Host/early stages. Unknown. 
Holotype m. , Colorado, Lake Co., 
Independence Pass, 12,100 ft, 
31. VII. 61; paratypes 2 m. , same data 
(J. G. Chillcott); Chaffee Co., 
Cottonwood Pass, 11,900 ft, 1 m. , 
29. VII. 61 (B. H. Poole). Holotype and 
paratypes in CNC, 1 paratype in KAS. 
Remarks. This species is distinctive 
in the broad frons and short second 
costal section. 
Phytomyza manni Spencer, new species 
(Figs. 1152, 1153) 
Head. Frons twice width of eye, 
distinctly projecting above eye in 
profile; 2 ors, 3 ori (lowest may be 
weak), orbital setulae in single row; 
gena deeply extended at rear, almost 
0.5 height of eye; 3d antennal segment 
longer than broad, arista slightly 
swollen basally. 
Mesonotum. 3+1 dc, acr in 2 rows. 
Wing. Length 2. 5-2. 7 mm, 2d costal 
section almost twice length of 4th. 
Color. Frons orange yellow, orbit 
grayish, entire hindmargin of eye 
dark; palpus and 3d antennal segment 
black, 1st and 2d yellowish; mesonotum 
and scutellum matt gray, side of thorax 
blackish gray; upper margin of meso- 
pleuron only narrowly yellow; legs 
black, femora with knees bright 
yellow; abdomen blackish gray; squama 
and fringe yellow, margin scarcely 
darker. 
Male genitalia. Aedeagus (figs. 1152, 
1153) with large ventral lobes and 
smaller flaplike lobe attached to 
right ventral sclerite; distiphallus 
with paired black lateral sclerites, 
ejaculatory duct short, membranous; 
sperm pump with large blade and base 
extended on one side. 
Host/early stages. Unknown. 
Holotype m. , Colorado, Clear Creek 
Co., Mt. Evans, Echo Lake, along 
grassy lake shore, 10,600 ft, 
13. VII. 61; paratype f . , same data; 
(both C. H. Mann), in CNC. 
Remarks. The affiliations of this 
species are unclear, but it possibly 
belongs to the V_, robustella group. 
Phytomyza masoni Spencer, new species 
(Figs. 1317, 1318) 
Head. Frons broad, 2.5 times width of 
eye, not projecting above eye in pro- 
file; 1 strong ors, 2 ori, orbital 
setulae short, sparse; orbit pro- 
nounced; gena angular, 0.33 height of 
eye; 3d antennal segment little longer 
than broad, rounded, with conspicuous 
fringe of white pubescence. 
Mesonotum. 3+1 strong dc, acr 
irregularly in 4 rows. 
Wing. Length in male 2.25 mm, 2d 
costal section 2.5 times length of 4th. 
318 
