312 The Ohio Journal of Science [Vol. XVI, No. 7, 



It is broadly spoon-shaped, with the anterior end slightly 

 pointed. Beneath it, the salivary pumping apparatus (s. p.) 

 occurs and is in close relationship with its lower surface. The 

 hypopharynx is heavily chitinized. The opening of the pharynx 

 into the suction canal of the labium is surrounded by hypo- 

 dermis, which encloses the setae. 



Pharynx — (PI. XX, Fig. 5). The chitinous pharynx, as in 

 all Hemiptera, constitutes a pumping apparatus, by means 

 of which plant juices and other food are withdrawn into the 

 digestive canal. The pharynx is a comparatively short, 

 simple, chitinous tube, supported by strong muscles. The 

 dorsal plate is somewhat elastic, and is capable of being with- 

 drawn from the ventral plate by the pharyngeal muscles 

 (ph. m.), which attach to the head-capsule along the inner 

 surface of the clypeus. Apparently the pharynx is about the 

 most powerful organ of the head, as the preponderance of 

 pharyngeal muscles is obvious. The pharynx passes back 

 over the body of the tentorium into the membranous esophagus. 



The Salivary Pumping Apparatus — (PL XX, Figs. 8, 15). 

 This characteristic Hemipterous structure is to be found beneath 

 the base of the hypopharynx. It consists essentially of a broad 

 spoon-shaped structure, into which fits the plunger (p.) ; the 

 latter is slightly smaller than the spoon or barrel (b. a.) and 

 functions as the driver of the apparatus. The plunger is 

 developed backward into a thick rod (r.), to which attaches 

 at its end the protractor muscles (p. p. s.). The united salivary 

 ducts (s. d.) open into the base of the barrel, and by the forward 

 motion of the plunger the saliva is forced forward through a 

 small canal (s. d. h.), which leads to the anterior edge of the 

 hypopharynx. At their entrance to the barrel the salivary 

 ducts are chitinized. The protractor muscles (p. p. s.) of the 

 plunger rod attach to the body of the tentorium, while the 

 retractor muscles (p. r. s.) attach on the under side of the rod 

 at one end and to the maxillary plates at the other. The 

 plunger is thus capable of a forward and backward motion, 

 by which means the saliva is pumped into the canal. 



Salivary Glands — (PL XXI, Fig. 22). In the Jassoid head 

 four separate salivary ducts are to be found; two pairs unite 

 behind the salivary pump into one common duct, but farther 

 back they separate into two pairs, which continue along the 



