260 DIPT ERA. 



liquids, but apparently prefers the blood of animals, 

 while the male, if it feeds at all, which seems to be 

 doubtful, must, according to Dimmock,^ take liquid 

 food, although in smaller quantities than the female. 

 The structure of the head and mouth parts of Culex 

 rufus is shown in PI. XIIL, Figs. 207-213, p. 260, 

 taken from Dimmock's paper, to which we have 

 already referred. PL XIII., Fig. 207, is a dorsal view 

 of the head ; PL XIII., Fig. 208, a side view of the 

 same, with the appendages. The mouth parts are 

 somewhat complex. Fig. 208, lae, is the labrum and 

 epipharynx, which are united throughout their length, 

 forming one piece ; hyp is the hypopharynx, a part 

 not found in many insects ; md are the mandibles ; 

 mx\ the first pair of maxillae. All these parts are re- 

 ceived into a groove on the upper side of the second 

 pair of maxill?e (;;/Jc") ; x^ are the maxillary palpi 

 (see PL XIIL, Fig. 207, x')-, d, the clypeus. PL XIII., 

 Fig. 209, is a cross-section through the middle of the 

 proboscis, showing the arrangement of the parts. The 

 mandibles {md) and first pair of maxillas (;;^.t') are 

 enclosed in the second pair of maxillae {mx"). Above 

 the mandibles is the hypopharynx (/ivp),a.nd resting 

 upon the latter is the epipharynx (ej>x) and the la- 

 brum (/a) (these two parts are lettered /ae in PL XIIL, 

 Fig. 208) ; f/i represents the tracheae, and z the mus- 

 cles of the second pair of maxillae. When the insect 

 bites, all the parts excepting the second pair of max- 

 illae (which bend backward under the breast) are thrust 



1 T/ie Anatomy of the Mouth Parts and of the Sucking Appa- 

 ratus of Some Diptera, Boston, A. Williams & Co., 1 881, p. 22. 



