136 ; DIPTERA. 
stripes—the intermediate ones linear, the outer ones interrupted at the transverse suture; scutellum 
ochraceous, with the base blackish ; pleuree whitish-grey. Abdomen ovate; first and second segments 
yellow and transparent, with some greyish reflections and a blackish dorsal stripe, which on the second 
segment is extended to a blackish hind border; on the third and anal segments the grey tomentum is 
more intense, the dorsal stripe disappears, and only a black hind border is conspicuous ; on the sides of all 
the segments are white reflections ; ventral surface yellow, with a grey tomentum ; rather long macrochate 
are on the hind margins of the second and following segments. Legs rufous, the coxe with whitish-grey 
reflections, the tibiee brownish, the tarsi black; middle tibiee outwardly with a long bristle; hind tibie 
outwardly with short bristles and a longer one in the middle. Tegule white. Wings grey, the colour 
more intense at the end of the costa and along the third vein; small cross-vein on the middle of the 
discal cell; apical cross-vein nearly straight ; posterior cross-vein slightly undulate. 
Hab. Mexico, Dos Arroyos in Guerrero 1000 feet (H. H. Smith). 
A single female specimen. 
7. Myobia opima, sp. n., 3 2. 
Cinereous ; abdomen rufous, with a blackish dorsal stripe; antennee, palpi, and legs rufous, the third antennal 
joint brown or black, the tarsi black ; no discal macrochete on the abdominal segments. 
Length 8 millim. 
Front cinereous, nearly as broad as the eyes, in the female broader ; frontal band black, in the male narrowed 
towards the vertex; frontal bristles on each side in a single row, reaching as far as the end of the first 
antennal joint; face and cheeks white; vibrisse inserted at some distance above the oral margin, which 
is a little prominent ; cheeks rather broad; eyes not descending to the vibrisse. Antenne rufous; third 
joint (except at the base) brownish or black, twice as long as the second; arista black, microscopically 
pubescent, slightly thickened at the base. Proboscis black, long and slender; palpi rufous, brown at the 
tip in the female, cylindrical, rather long. Thoracic dorsum with two blackish lines before the trans 
verse suture and an obsolete, interrupted, blackish lateral stripe; scutellum yellowish-cinereous, somewhat 
ochraceous. Abdomen conical, rufous, with white reflections, which sometimes appear as a white front 
margin to the segments; the blackish dorsal stripe is usually conspicuous only on the first two segments 
(in same of the specimens the third segment shows some blackish reflecting spots); on the hind margin 
of the first segment are two lateral macrochetz (one on each side), on that of the second segment are two “ 
dorsal macrocheete and one on each side, and on that of the third and anal segments is a row of macro- : 
chetz. Ventral surface with white front borders to the segments and with a black median stripe. Legs 
rufous, the tarsi black (in most of the specimens the tibize are brown); front femora with a row of 
bristles on the upper- and undersides; middle and hind femora with bristles only on the underside ; 
front tibie outwardly with some short bristles ; intermediate tibiee with two longer bristles at the middle, 
one on the outer and one on the inner side; hind tibie with several bristles of unequal length ; foot- 
claws and pulvilli elongate in the male, the pulvilli yellowish-grey. Tegule whitish. Wings hyaline, 
sometimes yellowish along the costa; curvation of the fourth vein with a blunt angle; small cross-vein 
nearly under the end of the first vein, and on the middle of the discal cell; apical and posterior cross-veins 
oblique, the apical nearly straight, the posterior slightly curved. 
Hab. Mexico, Hacienda de la Imagen 4000 feet and Amula 6000 feet, both in 
Guerrero, Cuernavaca in Morelos (H. H. Smith). 
Several male and two female specimens. 
8. Myobia angulata, sp. n., 2. 
Cinereous ; four thoracic stripes and hind borders of the abdominal segments black; frontal band and legs 
brown; the knees and the antenne rufous; third antennal joint elongate, as long as the second; curva- 
tion of the fourth vein with a right angle. 
Length 8 millim. 
