276 Mr. C. H. T. Townsend on Diptera 
36. Trichopoda formosa, var. radiata, Lw. 
Two males, San Rafael, July 2 and 4. On flowers of 
the Cordia sp. 
Length 15 to 17 millim. 
This is the largest known form of Trichopoda, the var. 
radiata being even more robust than the typical formosa. 
The larger one of these specimens is especially robust, with 
the wing coloration pronounced and the tibial cilia strongly 
developed. Not only are the hind tibie ciliate in these 
forms, but the cilia encroach very largely on the hind femora, 
the upper and lower edges of the distal third to half being 
ciliate, as Wiedemann has described. ‘hese apical cilia of 
the hind femora are more or less developed in other of the 
larger species of T'richopoda, but in none so strongly as in 
the present form radiata. The wings are rather conspicu- 
ously yellow in these specimens, in a broad elongate subcostal 
patch extending from near base to a point halfway between 
tips of first and second veins. But the milky colour is still 
more conspicuous, radiating from the base of the wing over 
the yellow and fuscous alike. The abdomen is obscure 
brownish red with a purplish tinge, the apical segment 
reddish yellow, which represents more nearly the colour of 
the abdomen in life. ‘The palpi and bases of femora are 
reddish yellow. 
T. radiata is doubtless to be considered conspecific with 
formosa. It must be preserved as a good variety on its 
general greater robustness, and the presence of the golden- 
pollinose markings of mesoscutum bebind transverse suture, 
which are apparently lacking in the typical formosa, a 
character which Loew failed to point out as differential. The 
somewhat lighter palpi and bases of femora, and more purplish 
abdomen of male, can hardly be used to distinguish it. 
Specimens of Yrichopoda vary to a considerable degree. 
Wiedemann’s specimens of formosa are described as having 
the thoracic lines white, the outer ones a little golden. In 
the species with conspicuous tibial cilia, these lines are 
normally deep golden yellow. But I have seen them wholly 
white, and even faint. I do not consider the colour of these 
lines of any importance. It is not a sexual, and it cannot be 
considered even a varietal character. In the smaller one of 
the present specimens, the deep golden pollen of mesoscutum 
behind the suture is highly developed, consisting of a pre- 
scutellar_ transversely-elongate subquadrangular area, with 
lateral edges continued forward in a narrow line on each side 
to suture, while posteriorly it spreads over the basal half of 
