from the Rio Nautla, State of Vera Cruz. 277 
disk of scutellum, though separted from latter by the silvery 
hind margin of thorax. In the other specimen this post- 
sutural golden pollen is so faint as to be apparent only in a 
golden shade next the silvery hind margin of thorax, with 
none on the scutellum. Loew mentioned the postsutural 
golden in his description of radiata, but failed to notice that, 
from Wiedemann’s description, it is evidently lacking in 
formosa and therefore of use as a differential character. 
Neither Loew nor Wiedemann mentioned the yellow of the 
wings, which doubtless varies much and may even be obsolete 
in some specimens. Wiedemann evidently means the first 
basal cell, when he says, ‘‘ Mittel oder Speichenzelle” milky. 
This is the case, at least. ‘The present specimens agree with 
Loew’s description in the milky radiations. Wiedemann 
says that these radiations follow the inner border of the 
longitudinal veins, which is true with the exception that it is 
the outer border in the case of the last section of fourth vein. 
The second costal cell is wholly milky. The specimens of 
radiata mentioned by me in Proc. Ent. Soc. Washington 
(ii. pp. 188-139) were taken at Dixie Landing, Va., early 
in July, on flowers of sumach (Rhus sp.). ‘The previous 
specimen from same locality, mentioned in same Proceedings 
(i. p. 255), taken August 19, was from flowers of tansy 
(Tanacetum vulgare, L.). 
37. Trichopoda formosa, var. inconstans, Wd. 
Three males, San Rafael, July 2, 3, and 6. On flowers of 
the Cordia sp. 
Length 13 to 15 millim. 
I would refer these specimens to aurantiaca, Towns. (Proc. 
Ent. Soc. Wash. ii. p. 140), which should be ranked as a 
variety of formosa, were it not for the conspicuous golden- 
yellow markings back of the suture, which are absent in 
aurantiaca. It would fit the description of luteipennis, were 
it not for the distinct broad area of black extending from 
base to tip of wing broadly bordering the yellow posteriorly, 
and the black colour of the legs. It may best be referred to 
inconstans, which also should be considered a variety of 
formosa. 
The present specimens agree with the description of zncon- 
stans in all except the triangular blackish areas of second to 
fourth abdominal segments. ‘hese are hardly perceptible, 
but still there seems to be a trace of them. Such markings 
can be of little use in separating dried specimens, being 
variable and doubtless due to the coagulation of the juices of 
