z9B 
signated as hypopharynx. Behind this begins the pharynæ which, 
as in all Culicid-larvæ hitherto examined, is covered above and 
below by two peculiarly formed chitin plates. The ventral plate 
is perforated by the oesophagus. As for the understanding of the 
buccal cavity and the pharynæ, see fig. 17. 
It is rather peculiar, that we have hitherto had but a slight 
intelligence of the manner in which a Culex-wriggler takes its 
food, and the mode of action of the many different organs in the 
buccal cavity during the process. By means of the exellent bino- 
cular aquarium-microscope which has been presented to the lab- 
Oratory by the Carlsbergfond, I have been able to study the cat- 
ching of the prey and the masticating process much more tho- 
roughly than my predecessors. The experimental object was for 
a long time the Mansonia larva; later on I used Culex-larvæ. 
Ås most of the observations have been made on the last menti- 
oned organisms I have thought it most correct to postpone the 
publication of these observations for a paper deeling with the struct- 
ure and biology of the Culex-larvæ, appointed for printing imme- 
diately after the present paper. 
ThOorax: 
The broad flat thorax (fig. 1) is subquadrate; laterally it car- 
ries three pairs of hairs-tufts and, in front, a pair of large brist- 
les with their points reaching beyond the flabellæ. In each bunch 
of bristles we usually find a single, more conspicuous and stiff 
bristle. Smaller bunches of bristles are implanted on the dorsal 
aS well as on the ventral side. 
Abdomen. 
The abdominal segments are uniform; dorsally and ventrally 
each segment has a small chitinized part (fig. 3). On each side 
of this there is a broader band more weakly chitinized. Laterally, 
nearest to the ventral side, a rounded prominence extents covering 
the origin of the long lateral hairs. Of these we find two or three 
long bristles, the foremost curved with the arcuation forwards. 
According to H. D. K. the American species possess only one 
bristle. Dorsally a little above these bristles each segment car- 
ries a pair of dusks with short bristles. A series of quite similar 
