ALEURODICUS COCOIR. 53 
ent species. On the other hand, we have specimens from the Canal 
Zone in which the pupa cases are of quite a different form from the 
usual type, being broader. There appear three varieties, one with a 
large and comparatively elongate pupa, one with a small elongate 
pupa, and one with a broad pupa. In these there appear no struc- 
tural differences. The larger material, that which we might call the 
iridescens material, has an average of 1.22 mm. by 0.92 mm., the 
smaller material an average of LOG mm. by 0.75 mm., while the Canal 
Zone material, lot No. 6768, has an average of 1 mm. by 0.89 mm. 
The largest specimen found in any material was 1.26 mm. by 0.98 mm. 
and the smallest 0.98 mm. by 0.7 mm. 
The arrangement of the pupae upon the leaf in reference to the 
median vein and the waxy secretion developed about them is similar 
in Cockerell's type of iridescens and in cocois (PI. XIV, fig. 1). The 
difference in host would easily account for the slight difference seen. 
Adults. — Some variation is shown in the adults, first, as to size and, 
secondly, as to wing marking. The type of Cockerell's iridescens in 
the U. S. National Museum collection is a small male and will be 
discussed under that sex. The vertex (PI. XII, fig. 11) is rounded 
and the antenna? (PL XII, fig. 12) are of seven segments, not six, 
as stated by Riley and Howard. Segment III is much the longer; 
II, IV, and V nearly equal in length, while VI and VII are some- 
what shorter. All the segments are imbricated, and V and VII are 
armed with fringed sensoria. The paronychium of the foot is the 
usual spine, and the basal segment of the tarsus is nearly twice as 
long as the distal one. The f orewings are armed on the costal margin 
(PI. XII, fig. 9) with conical hairy projections and two alternate 
rows of large bristle-like hairs. The remainder of the margin (PI. 
XII, fig. 10) lacks these hairs. The wings are marked with two 
dusky patches, one from the costal margin crossing the radial fork 
and the other at the distal extremity of the wing. In most forms 
these patches, especially the distal one, are very indistinct, but many 
degrees of intensity of shading occur, and in specimens from Pro- 
greso, Yucatan, lot No. 3286, the clouding is quite marked. Some 
dry specimens in which we were not able to distinguish any marking 
showed it quite plainly when balsam mounts were made. 
The female genitalia are of the ordinary Aleurodicus type. The 
forewing is 2.15 mm. by 1.15 mm., the hind tibiae 0.77 mm., and the 
tarsi together 0.307 mm. 
The males show a great range in size. This is shown in a compara- 
tive measurement of parts. The type of iridescens has claspers 0.4 
mm. long, and the width of the genital segment is 0.22 mm. In ma- 
terial of cocois, from different regions and hosts, a range from 0.4 
mm. to 0.92 mm. is met with in the claspers, depending upon the 
size of the individual. The average seems to be nearly 0.8 mm. In 
