.S94. 
347 
[Packard. 
the parts of the dipterous beaki, especially the liypopliaryrix, we 
are led to believe that the "unpaired piercing organ" of Siphonap- 
tera is a true hypopharynx, with the same homologies, arising in 
r ph 
Fig. 30. Labrara-ei)ipliaryax {Ihr and cph) and hypopharynx {h>jp) of 
Tabanus brominus; oe, posterior cyliiidrical portion of the oesophagus ; 
aoe. anterior swollen portion of the same ; ph, pharynx; 2^h.7n, pharyngeal 
mn>^c\e ; p.ph, protractor mnscle of the pharynx; roe, retractor muscle of 
the oesophagus; rph, retractor muscle of the pharynx ;/.oc, flexor muscle 
of the pharynx; t.oe, twisting muscle of the oesophagus; .sr, receptacle of 
the salivary duct ; /, its elevator muscle ; s, its retractor muscle ; cl, clypeus. 
— After Meinert. 
the same manner from the lower edge of the mouth and liaving 
morphologically no connection with the upper edge of the mouth, 
though as the result of adaptation and modification it does seem 
to arise from just under where the labruni is in Diptera. The 
strongest point, moreover, in favor of the view that it is a true 
' I am unable to agree with Prof. J. B. Smith's views of the homologies of tlie mouth- 
parts of Diptera. (Trans. Amer. eat. soc., v. 17, p. 319, Nov. 1890.) He has kindiv 
allowed me to see his preparations of the mouth-parts of Simulium. I was led to 
doubt his conclusions from my studies on the hypopharynx of the fleas, and from an 
examination of tlie works of Meinert, Hansen, and Miiggenberg, which he had appar- 
ently not seen. What he figures and regards as the "mandibles" of certain species of 
Simulium appear to be the homologues of the teeth at the end of the hypopharynx 
of other species of Simulium, i. e., the New England one, and that figured by Meinert 
(my Fig. 29). I also see no reason for Smith's regarding tlie proboscis, with the 
labella, as parts of the first maxillae. His "galea" is the lahella of all authors; his 
"palpifer" is the true maxilla; his "lacinia" I regard as the mandible, this also being 
the view of Meinert (thougli Meinert calls it the "cultellus"), Hansen, and previous 
authors. It would be singular if the two sets of teeth at the end of the hypopharynx 
were really homologues of the mandibles, because they are simply an armature sit- 
uated at tlie end of the h^'popharynx, and that this portion is that organ is proved 
by the fact that the salivary duct opens into it, and that it forms the floor of the 
mouth. 
