196 THE CANADIAN ENTOMOLOGIST. 



them into the thorax (Figs. 4 and 7). No tuft of branchiae thrust out and 

 withdrawn at will, as in Helichtis, could be seen, after watching living 

 specimens for hours, and after dissecting many examples. The writer is 

 inclined to think it does not exist, and that respiration is wholly accom- 

 plished by the ventral branchiae. 



It may be interesting to note the different sorts of hairs found upon 

 the body and organs. These are, of course, those of the usual pattern 

 common to all parts of the body surface. Found on the antennae there 

 are long, blade-like hairs, with their edges spined ; they occur elsewhere 

 (Fig. 13, a.) A modification of this sort is common on the legs, etc. 

 They are short, with the spines finger-like (h) ; another variety is long and 

 irregularly branched, found upon the labium and palpi (c) ; still another 

 form fringes the posterior border of the plenrltes \ they have a short stalk, 

 from the top of which radiate numerous fibres, fan-like (d). The hairs 

 of the border fringe are invested in a sheath slightly colored brown. 

 Immersion in potassa removes them from their sockets, leaving the edge 

 of (the segment serrate. 



EXPLANATION OF THE FIGURES. 



Fig. I . — Larva of Psephefius Lecontei, dorsal view, magnified eight 

 times ; a, suture ; c, dorsal suture (dotted line should extend further) : d, 

 suture base of pleurite : b, anus. 



Fig. 2. — Larva oi HelicJms /////^///////.y, enlarged eight times ; a, dorsal 

 stripe ; c, one of four light spots ; b, anal tuft of branchiae, protruded or 

 withrawn at will. 



Fig. 3. — Leg of Ps. Lecontei (enlarged). 



Fig. 4. — Cross section of second abdominal segment (enlarged) ; c, c, 

 pleurites ; b, b, branchiae. 



Fig. 5. — Head (enlarged); a, antennae ; b, maxillary palpus ; c, chitinous 

 band on under surface of labrum ; d, ocellus. 



Fig. 6. — Tip of antenna, showing forceps-like terminal joint (enlarged). 



Fig. 7. — Branchia. 



Fig. 8. — Mandible (enlarged one hundred times) ; b, chitinous support, 

 the cheek articulating with the mandible ; b, flexor muscle of the jaw ; 



c, ball article ; /, tufts of hairs. 



Fig. 9. — Ocelli. 



Fig. 10. — Maxilla; a, palpus; b, inner lobe; c, outer fleshy lobe; 



d, cardia ; c, pointed papilla. Magnified one hundred times. 



