Anatomy and Life-History of Pyrops candelaria. 113 
tip of which pass the setae. The elypeus (Pl. 9, Fig. 6 and 8 cl) and 
labrum (Fig. 6 ZLb) are well developed and form a large triangular 
piece which projects far over the basal part of the labium 
(Fig. 6 Zab); the dorsal surface is slightly convex, the lateral 
margins turned down at right angles to the dorsal surface. On 
each side, and fitting along the lateral margins, of the celypeus, 
are two acutely triangular plates, which, although fitting closely 
against the edge of the celypeus, are free for their distal three- 
fourths. If these plates be turned back, the large hypopharynx 
comes into view, with the setae Iying beside it. T'he lower pair of 
these, the maxillary setae (Fig. 8 and 11 Mxs) are in intimate 
connection with these plates, which I consider to be modified maxillae 
and shall call the maxillary plates (Fig. 8 and 11 M«). A strong 
chitinous bridge that passes under the oesophagus and above the 
infraoesophageal ganglion, connects the basal parts of the maxillary 
plates and gives attachment to various muscles and supports the 
basal part of the hypopharynx. I call this the maxillary bridge 
(Fig. 6 and 11 Mb). The acutely-pointed tips of the maxillary 
plates fit against the sides of the pointed labrum and form a 
small channel through which the setae pass. T'he mandibles, or 
upper pair of setae (Fig. 7 M) form a pair of long, slender, chitinous 
rods, swollen towards their base and bent up at right angles and 
articulated to the head-capsule near the outer corners of the base 
of the elypeus. From the swollen basal portion, just anterior to the 
angular bend, a strong retractor muscle (Fig. 7 Mr) arises and 
proceeds to the dorsal and basal portion of the epicranium; a strong 
protractor muscle (Fig. 7 Mp) arises slightly anterior to the angular 
bend and proceeds to the head-capsule near the apex of the elypeus; 
the angular bend is constricted and differentiated, and forms a hinge. 
By the aid of these two opposing muscles the mandibles can be 
moved backwards and forwards. T'he maxillae, as stated above, form 
two acutely-triangular plates, the setae being probably greatly 
elongated palpifers. They are long, slender, chitinous rods (Fig. 11 
Ms), swollen towards their base, where is attached a large retractor 
muscle (Mr), which proceeds to the dorsal and basal portion of the 
epicranium; a protractor muscle (Mp) is attached to the swollen basal 
portion higher up, and runs up the maxillary plates (Mx); these 
opposing muscles move the maxillary setae backwards and forwards.!) 
1) If the maxillary seta is regarded as the entire maxilla, then what 
