The fulcrum, which Gerstfeldt regarded as united maxillae, Menzbier considers 

 to be chitinized processes of the oesophagus. 



That the maxillae are grown together in Empis livida, is, perhaps, an error. 

 My having no specimens of Empis prevented my proving this point. Gerstfeldt 

 writes (p. 3.1-32), "Four setae which always represent the maxillae, the upper 

 lip and the hypopharynx, while the mandibles are united with the sheath of the 

 proboscis - - are found in the Etnpklae (in Einph the maxillae are also shorter 

 than the hypopharynx, but this exceeds the upper lip; all four setae are pointed 

 and horny)." * 



After recording some of his observations on the development of the epipharynx 

 and hypopharynx, Menzbier closes with a summary of his conclusions, which 

 would he superfluous, if transcribed here. 



With this short resume of the advances made in the study of the general 

 structure of the mouth-parts of insects, especially those of diptera, I will pass 

 on to the recording of results of my own observations on single genera, prefixing 

 to my own remarks, brief notices of the work done by others in the same direction. 



ANATOMY OF THE MOUTH-PARTS OF CULEX. 



From early times Cule.v has attracted the attention of mankind, but, until 

 about two centuries ago, little or no progress was made in the knowledge of the 

 inner structure of its mouth-parts. 



SWAMMEKDAMM, 11 who studied Culc.v in 1668. distinguished the male and 

 female, but evidently supposed that the structure of the proboscis of both sexes 

 was the same. He correctly distinguishes the long maxillary palpi of the males 

 from the short palpi of the females. He clearly recognized that there were six 

 mouth-parts enclosed in a sheath, but erroneously supposed them to be protrusile 

 from the end of the sheath, without flexion of the latter, and thus figured them. 

 The largest of these enclosed mouth-parts (really the combined labrum and 

 epipharynx) he supposed enclosed the other five, and he says (p. 147 of the 

 German edition of 1752), "I regard it that these five setae serve, like as many 

 sharp little awls to make the opening in the sweat-pores of the skin. When 

 this is done they draw themselves back again into the inner sheath. This then 



1 "Vier Borsten - - die inimer den Maxillen, der Oberlippe und dem hypopharynx ent- 

 sprechen, wahrend die Mandiblen mit der Riisselscheide verschmolzen sind - - besitzen" . . . 

 "die Enqiidi'ii (bei Empis sind die Maxillen ebenfalls kiirzer als der hypopharynx, dieser 

 iiberragt aber die Oberlippe; alle vier Borsten sind zugespitzt und hornig)." . . . 



