( 2 4 6 ) 
the male Topomyia Gracilis and the inferior claspers have fimbriated 
extremities quite unlike the blunt truncated end of the same parts in 
Gracilis. r 
Occurrence. The males and females of this species were taken by a 
jungle stream at Ampang about six miles from Kuala Lumpur in May. 
Remarks —This species closely resembles T. Gracilis , but the female 
differs in being blacker and having a large white spot on the scutellum and 
the male differs in the genitalia, fts size and lack of lateral abdominal 
spots distinguishes it from T. Minor and the lack of abdominal spots from 
T. Argentoventraiis. From T. Dubitans it is distinguished by the length of 
the fork cells, the narrower lateral wing scales, and the presence of the 
large scutellar spot. 
Topomyia Dubitans. n. sp. 
Pearly-white patch on the vertex of moderate size composed of white 
racquet-shaped scales the rest of the head clad with black racquet-shaped 
scales. Vertical bristles present. Central thoracic stripe continued over 
the whole length of mesonotum and extending on to the scutellum. Pleurae 
very dark brown. Mesonotum dark-brown. Abdomen dark brown above 
dingy-white below, without lateral spots. 
. . Female Head.— A moderate-sized semicircular patch of pearly-white 
iridescent racquet-shaped scales on the vertex and low down laterally a patch 
of similar scales present on each side; the rest of the head is clad with 
racquet-shaped black scales, vertical bristles black, there are a few black 
upright scales on the nape. Basal joint of antenna black, without scales, 
remaining joints black with black verticils. Proboscis not as long as 
abdomen clad with black scales. Palpi short and black scaled. 
Thorax. Prothoracic lobes black, the postero-external face clad with 
silvery broad elliptical scales, the antero-external face apparently nude 
except for a row of bristles. Mesonotum black or very dark brown, central 
stripe running the whole length composed of two rows of pearly-white 
iridescent scales the usual broadly elliptical shape ; shoulder clad with small 
elliptical dull yellowish scales, the rest of the mesonotum clad with 
black narrow-curved scales. Scutellum with a central line of white scales. 
Pleurae similar in colour to mesonotum clad with some elliptical white 
scales some almost circular. Wings with very long fork cells and 
distinctly clavate lateral scales, fork cells of equal breadth, first longer than 
second its base nearer wing base, its stem not more than quarter the length 
of the cell, posterior cross vein about twice its own length from median. 
Coxae light muddy-brown with silvery scales, all legs with dark brown 
scales with purple reflections except on the under sides of the femora 
which are pale scaled ; ungues equal and simple on all legs. 
Abdomen. Clad above with dark brown scales, purple in some lights, 
and on the venter with silvery scales which in the dry specimen acquire a 
more creamy tint. There are no lateral spots. 
Occurrence. -This specimen was taken at the “ Gap” in May under the 
same conditions as the other known members of this genus. 
