NEUROPTERA. — SIALIDE. 51 
setose tail; the legs are of moderate length, and terminated by two 
claws; the head is scaly, and furnished with eyes and antenne. The 
mouth of the larva consists of an angular upper lip; a pair of strong 
mandibles, armed with two teeth at the middle of the inner margin 
(fig.64.19.); the maxilla are curved, and furnished with a kind of 
bifid palpus, according to Pictet; but more properly consisting of two 
lobes, the inner acute, curved, and armed with three strong spines ; 
the outer lobe has its inner angle produced into a point; the maxillary 
palpus consisting of four joints (fig. 64. 20.); the labium, with its 
short 3-jointed palpi are represented in fig. 64.21.; the above figures 
being the first which have yet been published of the details of the 
curious nrouth of this insect either in the larva or perfect state. The 
antenne are setaceous, and 4-articulated; the three thoracic seg- 
ments are of nearly equal size; the tenth abdominal lobe constitutes 
the setose tail. When full grown, this larva quits the water, and bur- 
rows into the adjoining bank, in which it forms a cell, wherein it is 
transformed into an inactive pupa (fig. 64. 22.), with the limbs laid 
along the breast ; it is, however, very lively, twisting its tail about 
when disturbed. The insect assumes its perfect form in its cell (De 
Geer, Mémoires, tom. ii. p. '716.; Rosel, Ins., tom. ii. class 2.; Jus. 
Aq,., tab. 13.; Pictet and Suckow, loc. cit. supra ; Frisch, tom. i. pt. 8. 
tab. 14.). 
The family comprises two distinct subfamilies : — 1st, the Sialides, 
described above; and 2d, the Corydalides, having the tarsi simple, 
three ocelli, and the wings carried nearly horizontally when at rest. 
The latter insects appear to form a link between Hemerobius and 
Perla. Latreille considers Corydalis as allied to Raphidia ( Gen. Cr., 
tom. iii. p. 199.). They are of large size, and often handsomely varie- 
gated; they are chiefly, if not exclusively, inhabitants of North 
America. The largest of these (Corydalis cornuta Zatr.) is distin- 
guished by the immense size of the mandibles in one sex. De Geer’s 
figure 2. pl. 27. tom. iii., evidently represents the head of the female. 
Chauliodes is distinguished by the strongly pectinated antenne. 
There are several other undescribed genera belonging to this section, 
to which also belongs a species figured in Griffith’s An. Kingd. Ins., 
pl. 72., under the name of Chauliodes maculipennis: G. FR. Gray; but 
previously described by Say. 

