from the Rio Nautla, State of Vera Cruz. 29 
opalescent cupreous reflection, but still entirely contrasted in 
colour with the thorax; clothed with yellow hair only on 
base and edges, with black hair on whole dorsum. Second 
and third abdominal segments broadly dull brownish yellow 
on anterior corners, in a triangular form on second but little 
separated from hind margin, in a subquadrangular form on 
third confined to anterior half. Fourth segment with a 
smaller less distinct triangle of same colour on anterior 
corners. Pubescence of abdomen somewhat longer and 
thicker, that of the light parts being yellow. 
32. Volucella opalina, sp. n. 
Three female and five male specimens, San Rafael. The 
males, one each, July 6, 7, and 9, and two, July 10. The 
females, two July 9 and one July 17. All on flowers of the 
Cordia sp. 
Length nearly 10 to 113 millim. 
Differs from V. cordiw as follows:—Face and cheeks 
entirely without stripes. Front shining brighter greenish, 
with silvery pollen on each side, extending in narrow border 
along orbital margin to vertex. Frontal triangle of male as 
in nautlana. Antenne in both sexes considerably smaller, 
the third joint not so much narrowed apically. Pubescence 
of thorax of male as described for nautlana, with the black 
pubescence more conspicuous than the shorter yellowish or 
whitish ; in the female the yellow pubescence is, if anything, 
more conspicuous than the black, being exactly the same as 
in male of nautlana. In two of the females the short 
pubescence is whitish and the longer black is much less con- 
spicuous, but is seen to be present; these same females differ 
further from the other in hair of front being whitish, and they 
may be considered to constitute a variety. Scutellum as in 
nautlana, both as to colour and pubescence, but even more 
nearly concolorous with thorax, with greenish, cupreous, and 
violet reflections. Abdomen wholly without yellowish ; with 
brillant green, violet, and purple reflections, especially on 
third and fourth segments. _ Underside of second and third 
segments with mostly black hair in male, the white hair 
being confined to basal edge, but the white more extensive in 
female. Wings often with the yellow invading and tinging 
the brown, and with some of the cells hyaline in the centre. 
Var. splendens, var. n. 
I propose this name to distinguish the two females (both 
July 9) above mentioned as having the hair of front white. 
