128 THE MICROSCOPICAL NEWS. 
and edges ; at the tip hooked, but lozenge-shaped, where they are 
continued along the margin in a broadening band which is, how- 
ever, reduced to a single row of hooked teeth, terminating about 
the middle of the maxilla. This band does not occupy the entire 
marginal surface on this side, although it closely borders the edge 
of the groove. On the other, and, as shown in the Figure on the 
margin, the teeth assume a longer and more acutely pointed shape 
in a single row carried along the edge of the grooved hollow to a 
point rather nearer the head than the termination of the opposite 
row. Interspersed amongst the teeth on the outer band are 
numerous short bristly hairs. ‘These merge in a dense, hair-like 
fringe, carried down the maxilla almost to its base, being longest 
and finest about the middle third of its length. The Figure is a 
drawing of the upper third of the maxilla. We have now to con- 
sider the remaining seta, the mgua, /igu/a or tongue (4“ngua, Fig. 37) 
described by Gosse as the /abzum, although Burmeister clearly 
shows that this term is rarely only applicable to the proboscis of 
the suctorial mouth. 
And here I may remark that the drawings, useful as they may be 
for purposes of illustration, must not be considered as at all a faith- 
ful representation of the various organs as they naturally appear. 
Being taken from a prepared slide, they are necessarily imperfect 
as regards the true relative position of the parts, and also, to a 
great extent, in respect of their shape. The mandibles and maxillz, 
from their structure and shape, may be little altered, but the hollow 
labrum and “gua and the soft /adium are necessarily flattened 
and so distorted. I mention this because, from the appearance of 
the Zingua, the organ now under consideration, the mistake might 
easily be made of assuming for it a distinctly tabular structure. 
Such, however, is not the case. It may rather be described as 
resembling in form a thin pointed pea-pod, open to the end along 
one margin but closed on the opposite side. In the 4mgua, this 
longitudinal opening is opposite to, and so far corresponds with, 
that of the labrum already described. That it is used as a suctorial 
tube may readily be believed ; but there can be no doubt that it also 
serves as an inner sheath for the mandibles and maxille, the five 
together then fitting into the cavity of the labrum. In structure, 
the mgua presents no special characteristics, being throughout 
composed of hard, clear chitine, and having the two free edges 
clothed with a delicate fringe, similar in character to, but much 
finer than, that of the maxillee. 
In passing, a word should be given to the maxillary palpi, one of 
which is attached to the base of each maxilla. They are two- 
jointed, the second joint club-shaped, and much dilated at its basal 
end. , 
There remains to be noticed the /adcum or proboscis, correspond- 
