130 KANSAS UNIVERSITY SCIENCE BULLETIN. 



the membrane between the stipes, cardines and mentum. It 

 does not appear to be articulated to or otherwise connected 

 with the large mentum, but lies immediately behind it. The 

 mentum is the large, heavily chitinized piece forming the body 

 of the labium. Just before and on each side of its wedge- 

 shaped extremity are the four-jointed labial palpi (LP). On 

 either side, at about the middle of its length, the mentum sends 

 an extension dorsad, which is secured in a degree to the inner 

 lateral edge of the stipe of the maxillae. 



Glossa. Anterior to and arising from the mentum is the 

 largely membranous ligula, consisting of the fused glosste and 

 the free paraglossaB. It is tongue-like at its tip (labellum) . At 

 the base of the ligula is the translucent ventral supporting 

 plate of the ligula, which is grooved to the extremity of the 

 ligula (fig. 7, gl, gr) . The dorsal extremity of the latter (fig. 8, 

 GL) is beset with rather appressed, apically expanded hairs 

 arranged in transverse rows. 



Hypopharynx. The glossse are sometimes termed the hypo- 

 pharynx, but Snodgrass (Anat. of the Honeybee, U. S. D. A. 

 tech. ser. No. 18, pp. 49-50; 1910) has shown that the honey- 

 bee does not possess a hypopharynx. To quote this author: 

 "The duct of the salivary glands of insects in general opens 

 upon the base of the labium in front of the hypopharynx. In 

 the honeybee the salivary opening is on the dorsal side of the 

 base of the ligula, between the paraglosste. . . . This 

 alone would show that the glossa is not the hypopharynx of 

 the bee, as many authors have supposed, for otherwise the 

 opening of the salivary duct should be ventrad to the base of 

 the glossa. In fact, this makes it clear that the bee does not pos- 

 sess a hypopharynx. There is, however, a conspicuous chi- 

 tinous plate located on the anterior part of the floor of the 

 pharynx, having two terminal points hanging downwards over 

 the lower lip of the oral aperture ; but, although this plate is 

 truly hypopharyngeal in position, it is not the homologue of 

 the organ called the hypopharynx in other insects." 



This statement appears to apply as well to Tachytes, which 

 has the opening of the salivary glands similarly situated be- 

 tween the scales of the paraglossse (pi. XXIII, fig. 8, near h) . 

 The portion above and beyond the mentum, being largely mem- 

 branous, bears several strengthening sclerites of small size 

 (pi. XXIII, fig. 8, g, h, e) ; g, the most anterior of these, lies 



