HYDROPHORIA. 333 
second joint with a bristle; third joint double as long as the second ; arista long-plumose, thickened at 
the base. Proboscis and palpi black. Thorax and scutellum cinereous, the thorax with three black 
stripes, the lateral ones interrupted at the transverse suture ; metanotum grey. Abdomen conical, convex, 
cinereous ; first segment black; the following segments with a black dorsal stripe, which is attenuated 
towards the end; front borders of the second and third segments blackish-brown ; marginal macrocheetse 
on the third and anal segments. Legs black; foot-claws and pulvilli scarcely elongate, the pulvilli 
yellowish. Tegule whitish; halteres brown, with yellow knob, Wings greyish-hyaline ; small cross- 
vein beyond the end of the first vein and beyond the middle of the discal cell; third and fourth veins 
parallel; terminal section of the fourth vein longer than the penultimate section (about 3:2) ; posterior 
cross-vein oblique and distinctly undulate. 
Hab. Mexico, Amula in Guerrero 6000 feet (7. H. Smith). 
A single male specimen. 
2. Hydrophoria collaris, sp.n. 3¢ @. (Tab. VIII. figg. 11, 3; 11a, head in 
profile, ¢ .) 
Thorax whitish, black in the middle; abdomen yellow, with brown dorsal line and transverse bands ; antenne, 
palpi, and legs rufous, the terminal part of the antenna, the tips of the middle and hind femora, and the 
tarsi black. 
Length 5-7 millim. 
Head white, often silvery; front of the male triangular, black in the middle; eyes contiguous; face slightly 
retracted, as long as the front; vibrisse strong, just at the oral margin, which is not prominent ; inferior 
part of the cheeks narrow, with some fine bristly hairs. Antenne inserted a little beneath the median 
line of the eyes, rufous; second joint with a bristle; third joint elongate, three times as long as the 
second, descending to near the vibrisse, blackish towards the tip; arista long, short-haired, thickened at 
the base. Proboscis blackish-brown ; palpi cylindrical, yellowish, sometimes black at the base. Thorax 
with a whitish tomentum, which is absent immediately behind the transverse suture, forming thus a broad 
blackish transverse band ; shoulder-edges somewhat rufous; scutellum blackish, with rufous hind border ; 
metanotum whitish-grey. Abdomen elongate, somewhat cylindrical, yellowish, with a brown dorsal line, 
which on the second and following segments is dilated into trigonal spots and often to a band at the front 
borders; marginal macrochxte present on the second and following segments, lateral macrochate 
on all the segments. Legs slender, rufous, including the front cox, the middle and hind femora, and 
the tibiae more or less, with black tips, the tips of the front femora also sometimes slightly infuscate, the 
tarsi black ; front tarsi longer than the tibie; foot-claws and pulvilli elongate in the male, the pulvilli 
yellowish. Tegule whitish ; halteres rufous. Wings yellowish-grey ; small cross-vein under the end of 
the first vein and distinctly beyond the middle of the discal cell; third vein slightly curved upwards at 
the tip; terminal section of the fourth vein longer than the penultimate section (35:2); posterior cross- 
vein undulate. 
The female resembles the male, save the usual sexual differences ; the front is as broad as the eyes; the frontal 
band is black, sometimes slightly rufous (in recently emerged specimens); the black coloration of the 
antenne is variable, it being sometimes more extended, leaving the basal joints only rufous, or, on the 
contrary, nearly the whole of the antenne is rufous. ‘The whitish colour on the prothorax is interrupted 
by two broad black bands. The abdomen is conical. The terminal section of the fourth vein is but a 
little longer than the penultimate section (25:2); the posterior cross-vein is nearer to the tip of the 
wing. 
Hab. Mexico, Amula, Xucumanatlan, Sierra de las Aguas Escondidas, and Omilteme, 
all in Guerrero, 6000 to 8000 feet (Z. H. Smith). 
Several specimens of both sexes. 
