26 Mr. C. H. T. Townsend on Diptera 
colouring and closely similar form show that they all belong, 
with one exception, to the same group. One of them possesses 
no prescutellar row of bristles, and further differs in being 
pronounced metallic green including head, with coppery on 
abdomen and showing but little if any violet. It inclines 
to the obesa group. The others belong to the group of 
V. amethystina, Bigot, which also includes comastes, Will., 
chetophora, Will., &c. To the last-named species I refer 
one of the six above mentioned, while the other five are new. 
‘These species may be distinguished by the following table. 
They are all distinct from Volucella, n. sp.?, Will., Synop. 
p. 150. 
1. No prescutellar row of bristles present; thorax 
and scutellum bright metallic green; abdomen 
COP POUY ye a eteypoeleraja'se: oye ays \s om RMS ge eRe vi led Sel aus viridana, sp. D. 
Prescutellar row of bristles present; metallic 
colouring bluish, dark green, or violet........ 2. 
2. Wings hyaline, with only a milk tinge in oblique 
MSA crac Sora elst® chet beads, «sa SERRE Rae ib td Sle chetophora, Will. 
Wings strongly shaded with brown and 
SVS OVINE oo 6 le se ers asa! ORE BERTON evs >, 3. 
3. Scutellum metallic, nearly or quite the colour of 
fire" Phorase )t313)5)20..'.-.). a, eee tale ce ence 4, 
Scutellum wholly (dull or clear) brownish yellow, 
contrasted in colour with the thorax; face and 
Cheeks swith Simipes 7.3 «..0s asheneeeete 5. 
4. Face and cheeks without stripes, abdomen without 
Mee tetas ah icue teen acess RPS Sates Bt cin ty opalina, sp. n. 
Face and cheeks with pronounced stripes ; 
abdomen yellow at base . ..\:4jtec s/s. alee eel rafaelana, sp. 0. 
5. Second abdominal segment in most part the same 
colour as the scutellum; rest of abdomen 
without yellowish or with but a trace on 
anterior corners of third segment ............4 cordi@, sp. Nn. 
Second and third abdominal segments same 
colour as scutellum in a nearly equal sub- 
triangular patch on anterior corners, with a 
smaller patch usually distinct on anterior 
Corblers OL Mourth ey, su len can eee cate tela nautlana, sp. 0. 
I have no specimens of amethystina, Big., and therefore do 
not include it in the table. It is described by Bigot as 
having the scutellum the same metallic violet as the thorax, 
the cheeks with a stripe, but facial stripe apparently absent, 
and with differences in the abdomen and wings which preclude 
my referring any of the present species to it. It may be 
added that all of these species have the second vein regular 
and the margin of scutellum with bristles. 
28. Volucella chetophora, Will. 
Two females, San Rafael, July 7 and 10. On flowers of 
the Cordia sp. 
a 
