332 
Transactions, &c. 
PiVTonthly Microscopical 
L Journal, June 1, 1869. 
folded up in its cavity; Plate XYI., Fig. 30, a side view of the head, 
with the proboscis exserted, both very good; and Plate XYI., Fig. 31, 
an inaccurate view of the back of the proboscis. It is most pro- 
bable that the structure of the interior was unknown to this author, 
as the extension of the organ is attributed to inflation, and not to 
muscular action. The parts of the chitinous exo-skeleton named 
in my figures the Epiglottis and Mentum, are correctly represented, 
and named respectively the " upper and lower little scaly bone." 
He also states that M. de Eeaumur had discovered a sting, 
probably the ligula, the position of which is accurately described. 
With respect to the lips, the pseudo-trachese are represented in his 
figure merely as lines, and, by the description, were evidently taken 
for muscular bands. The milky fluid contained in the proboscis of 
a young fly is noticed, and also the copious flow of saliva. The 
function of the maxillary palpi is considered to be that of brushes for 
cleaning the proboscis. 
Plate XV. — Diagrams illustrating arrangement of the chitinous endo and exo 
skeleton : — 
1. Side view, principally from specimen macerated in liquor 
potassse. 
2. Diagram of Ligula, Labium, &c. \ From sketches supplied 
3. Ideal section of lower joint of proboscis./ by Mr. B. T. Lowne. 
a. Fulcrum (Pharynx). 
6. Basal ring of Maxilla, 
c, c'. Maxillary palpi. 
d. Epiglottis (composed of labrum and terminal lobes of 
maxillse united). 
e. Labial palpi. 
/. Ligula. 
g. Chitinous process supporting tracheal or anterior surface 
of the lips (front view in Plate XIV.). 
h. Labium. 
i. Mentum. 
k. Small chitinous piece protecting oesophagus. 
I v. Apodeme of mandible. 
m. Lobe of Maxilla. 
w. Chitinous processes serving as springs to close the lips. 
0 0'. Main channels of pseudo-tracheae. 
Note. — Two pairs of muscles are shown in the Plate as attached 
to the hooked processes of the Fulcrum (a) and the extremities 
of the chitinous rods / and I' ; these only represent a very small 
portion of the muscular system, and not the whole, as might be 
inferred from the absence of others, and are figured to show the 
office of these portions of the skeleton. 
Plate XVI. — Fig. 1. One of the large main pseudo-tracheal channels, showing 
arrangement of the chitinous bands and the smaller pseudo- 
trachese joining the larger tube ; on the left, at the top, are 
two of the teeth. 
„ 2. View of main channel and branches from the back, showing 
the arrangement of the chitinous bands at the junctions 
with main pseudo-trachea. 
„ 3. Hooks of chitinous bands of pseudo-trachese, after Mr. G. 
Hunt. 'Micro. Quarterly Journal,' 1856. 
„ 4. View of portion of the lips, showing triple row of teeth and 
mouths of pseudo-tracheee ; scale the same as Fig. 2. 
