5 Se ee eee 
i as On Gy a ae 
1884.] Recent Literature. 1237 
4, fs) to a band in the anterior margin of the cranium (cd). Its 
side-walls are strong chitin-plates, with a sinus looking back- 
wards. The sole of the “ stirrup” is double, of two chitin-plates 
superposed, and having a cavity between them, within which the 
esophagus passes forwards (Fig. 5, of, uf). The infero-poste- 
rior extremities of the “ stirrup” are prolonge 
into horns, one at each side (Fig. 4, 2s), which 
are connected by retractor-muscles (mr) to the 
cranial band (cd). The maxillary tendons are ,,_ 
at their proximal extremities connected by a ,¢..\. 
short muscle with the supero-posterior extrem- 
ity of the fulcrum, and by along muscle (me) ¿d7 
with its anterior horn. Below the floor of the Fig. 5—Fulcrum. 
fulcrum are seen muscles running forwards, and also the trachea- 
like salivary duct (Fig. 5 sd). 
The Proper Proboscis (medi-and disti-proboscis, Fig. 3, ™P and 
dp)—When viewed from the side, this part (representing the 
labium) is a cylinder, anteriorly divided into a two-lobed tip, the 
labellæ. Viewed from above we see that it has a superior longi- 
tudinal canal in which two unpaired chitinous stylets are em- 
bedded (Figs. 1, 4, 2,0 and 4). The upper one of these two 
stylets, the labrum (oberlippe, o) appears as the direct continua- 
tion forwards of the upper anterior margin of the basi-proboscis, 
and, like all insect appendages, is hollow, enclosing muscles, 
trachee and nerves. As the labium has a deep groove on its 
upper surface (Fig. 2, up), so the labrum has a similar groove on 
its under surface (o), and is in fact an inverted semi-cylinder with 
double walls, (Its lower wall was once deemed a distinct piece, 
epipharynx.) ay 
The under proximal extremity is articulated to a small chitin- 
capsule, described by Macloskie and Becker as a triangular 
“binding-piece,” and overlooked by other observers (Fig. 4, se). 
This “small capsule ” lies directly in front of the fulcrum, whose 
form it repeats in miniature. The floor of the small capsule is 
continuous with the under floor of the fulcrum, and the upper 
plate of the fulcrum-floor partially roofs the small capsule. The 
Side-walls of the small capsule bulge out and are chitinized, giv- 
rts of the labrum, 
whilst the floor of the small capsule supports the second stylet, 
Nutritive tube (zc) which opens on th 
and forms te lator 2 rather the antechamber, of the ali- 
Mentary canal. Imbibed fluid penetrates this canal, then eet 
the “ small capsule,” which serves as a reservoir, passing nex 
into the space between the double floor of the fulcrum, and so on 
