i75 
folds in front of the fork, but there is a deep oblique fold immediately 
behind it (fig. 5, c 7 ). When the labella are everted (figs. 2, 3, 10, II, 
12, 14) the folds become very complicated and difficult of interpreta 
tion, but there are three deep ones in front of the pulley. Dorsally. 
a little posterior to the point where the tip of the fork impinge* 
against the inner surface of the external wall (fig. 14, e), a complete 
pocket or cul-de-sac is formed (fig. 13). Ventrally there is als - 
another deep fold which, when seen in transverse section (fig. 12, c 
appears as a projecting and slightly divergent arm. 
External Hairs. These occupy three principal areas -. 
(1) A ventral series ( d in all the figs.) immediately within the 
thin flexible terminal flanges of the labella (figs. 2, 3, 5, 6, 9, &c.). Then- 
are from 15 to 16 of these on either side, three of which are much 
longer than the rest; all are stout, curved, rest on broad cylindrical 
bases, and are equidistant, with the exception of two or three, which 
give the otherwise complete line a somewhat irregular appearance 
1 hese hairs are easily traced in' all preparations ; and during eversion 
they are directed backwards instead of forwards, forming an almost 
complete fringe below the teeth. Lying folded back on the proboscis 
the tips of the largest reach nearly as far backwards as the fork 
(2) A dorsal bilateral row of five or six setae ( [d l in all the figs 
1 hese are situated partly within the apical fold of the labella (fig. 4 . 
and when the labella are everted they take a more or less transverse 
position, with the tips of either row overlapping or meeting along 
the median line of the groove of the labella, forming a ladder-like 
arrangement (figs. 2, 14). These hairs can be seen only in preparations 
that have been thoroughly bleached. 
( 3 ) A lateral group of minute hairs (d 2 in all the figs.). These 
lie immediately behind the tip of the fork when the labella are 
t'crted (figs. 2, 14), occupying a sub-dorsal position; but when the 
a ella are closed, this group takes a more lateral position (figs. 4, 6) 
m t le region opposite the sclerites which form the walls of the dorsal 
canal of the labium. The individual hairs are extremely minute (the 
ength less than the width of the clear area in which they are placed' 
and difficult to see; each one is placed in the centre of a large, clear 
circular or gland-like ” area, which is well marked off from the 
slH roun ding chitin, and thereby rendered conspicuous. 
