salivary duct in other diptera, leads me to believe, without as yet being able to 

 give anatomical proof of it, that the hypopharynx of Culex contains a duct that 

 pours out its poisonous saliva. Not having fresh specimens of Culex ciliatiis, 

 and the extreme minuteness of the hypopharynx in the species of Culex available, 

 has precluded my determination of the actual presence of glands in connection 

 with this mouth-part. 



The mandibles (figs. 1 and 8, w), the most delicate of the mouth-parts of 

 Cnli'.r, are two very thin linear-lanceolate lamellae of transparent chitin, which 

 rest with their inner edges beneath each half of the hypopharynx, their outer 

 edges projecting beyond its outer edge, on each side. The mandibles are so thin 

 and transparent, and so tightly pressed upon both the hypopharynx above and 

 the maxillae below, that they easily remain undiscovered in sections of the pro- 

 boscis. At the base of the proboscis they appear to have no muscular attach- 

 ments, but to lie imbedded in the connective tissue, beneath the pharynx and 

 above the maxillae. (See fig. 9.) They are slightly tapering from the base to 

 the tip, but are of equal thickness throughout their breadth ; at tLa tip they 

 have a slight thickening, in form of a letter V, with its opening turned toward 

 their very delicate, almost invisible tip. (See fig. 5, m.) 



The maxillae (mistaken by Gerstfeldt * for the mandibles), are tapering 

 lamellae of chitin, apparently serrate at the tips. Each maxilla is thicker near 

 the inner edge, the thickening being formed by a solid chitinous shaft, which is 

 fixed longitudinally upon the upper side. (See fig. 5 and 8, mx.) The bases of 

 the maxillae join the stouter maxillary palpi just before passing under the cly- 

 peus, and immediately afterwards they join the labium, and become imbedded, 

 with the mandibles, in connective tissue. (See fig. 9, MX.) Their continuations 

 in the head are two delicate chitin-supports, each of which ends in a strong 

 muscle; this muscle, the retractor maxillae (fig. 10, rt>i), passes backward and 

 downward through the 'head, beneath the infraoesophageal ganglion, and has its 

 origin in the posterior basal part of the head. The maxillae probably have no 

 protractor muscle, their forward motion being due to the elasticity of the chitin 

 frame-work of the head. The shaft of the maxillae is very transparent, except 

 near the inner side where the chitin-rod runs; here it is brownish and more 

 opaque. Out from the above-mentioned chitin-rod extends a very delicate 

 feathering, or corrugation, of chitin to the edge of the most transparent portion 



'" Gerstfeldt 3 (p. 33) says, "of which the mandibles, toothed at the end, are somewhat 

 broader but of the same length as the toothless maxillae." In the original, "von welchen 

 die am Ende gezahnten Mandibeln ctwas breiter, aber ebenso lang als die zahnlosen 

 Maxillen s ; nd." 



