Fabricius writes, in the preface of his Systema entomologiae, * after dis- 

 cussing the confusion which existed in the classification of insects at his time, 

 "Therefore I will try a new method, choosing characters, both of classes and 

 of genera, from the month-parts. These parts truly offer sufficient and con- 

 stant characters and far more natural genera." * In his Philosophia cntom- 

 ologica 2 (p. 37-52), where his ideas are further elaborated, one finds that 

 Fabricius divided the mouth-parts of insects into palpi, clypeus (now the labrum), 

 mandibulae, maxillae, galea, labium, lingua, rostrum, proboscis and hanstellum. 

 The proboscis and haustellum, the parts which concern us most here, are somewhat 

 confused in Fabricius' classification. The proboscis, he writes (p. 38), is membran- 

 aceous and bilabiate ; the haustellum is extended, chitinous, and without articu- 

 lations ; ** with the former is no mention of setae, with the latter, he adds, setae 

 differing in number. He writes (p. 49), ''The proboscis, so peculiar to the 

 diptera, is not possessed by all of them," *** and, on the next page he gives 

 Bombylius as without proboscis. Again he writes (p. 52). "The proboscis 

 differs from , the haustellum in that the proboscis is always bilabiate, the 

 haustellum never," f and that, " The haustellum, being the characteristic of 

 the class, is always present in the diptera; the proboscis is often entirely 

 absent." ff Furthermore Fabricius writes (p. 30), "In the diptera are 

 two palpi, a haustellum very often received in a proboscis, while mandibles, 

 maxillae, clypeus and labium are absent." fff From the above quotations it is 

 clear that Fabricius meant by the proboscis what is now known to be, for the 

 most part, labium; by haustellum, following the derivation of the word, he meant 

 the true suction-tube, whether of one part, or made up of setae. The confusion 

 which arises in the Fabrician use of proboscis and haustellum is mainly due to 

 his failing to recognize, in his so-called "haustellum" of Cuh\r. and Bombylius, 

 parts which correspond to his "proboscis" in Musca, *Syrj>/m* and other diptera. 



1 For full titles referred to by superior figures, see Literature at the end of this paper. 



N "Novam ideo viam tentabo, characteres et classium et generum ex instruments 



cibariis desumens. Praebent sane sufficientes, praebent constantes et genera multo naturaliora." 



** "Proboscis membranacea, bilabiata" "Haustellum porrectum, corneum, 



inarticulatum." 



*** " Proboscis tantum Antliatis propria, nee omnia ilia ea gaudent." 



r|- " Proboscis diftert ab haustello, quod proboscis semper bilabiata, haustellum vero 

 nunquam." 



-|-f " Haustellum, classis continens characterem, semper in Antliatis adest, proboscis 

 saepe omnino deest." 



fft "Palpi duo, haustellum saepius proboscide receptum, absque mandibulis, maxillis, 

 clypeo et labio in Antliatis." 



