330 



ON THE MOUTH-PARTS IN SCHIZONEDRA LANIGERA. 



2}st. Insertion of pump-muscle on tlie 

 flexible proximal wall of salivary 

 pump. 

 s.(/a. Supra-CBSophageal ganglion. 



s.c. Suction-canal formed between the 

 maxillary stylets and leading 

 into pharyngeal duct. 

 s.e.cl. Efferent salivary duct leading 

 from salivary chamber into the 

 salivary ejector-canal formed 

 between the maxiUary stylets. 



s.p. Salivary pump. 



s.c/l.p. Posterior salivary gland. 



t.p. Transverse chitinous plate of endo- 

 skeleton. 

 th.ffa. Thoracic ganglia. 



v.r. Ventral rods of chitin extending 

 from posterior angles of the 

 buccal folds. 

 v.m. Small ventral muscles of salivary 

 pump, which act on the opening 

 of the salivary duct into the 

 pump-chamber. 



Platk 24. 



Fig. 1. Median longitudinal section tliiough the head, slightly schematised, showing 

 salivary pump, pharynx, etc. x 600. The indicating lines at the side indicate 

 the plane through which the transverse serial sections figs. 4-22 have passed ; 

 the numbers refer to the number of the transverse section given. Figure drawn 

 in outline from longitudinal section with Camera lucida. 

 2. Fore-head, ventral view, showing stylets, musculature, etc. — Note. The maxillary 

 sclerites really come close together in the median line over the hypopharynx lip, 

 but they are shown displaced from the median lino so as to show the underlying 

 hypopharynx lip. TJie lines at the side indicate the plane of the serial sections 

 as in hg. 1. Figure drawn from potash preparation. 

 S. Fore-head, dorsal view, showing mandibles, musculature, and endoskeleton. Side- 

 lines indicate as in fig. 1. Figure drawn from cleared preparation. The length 

 is increased slightly out of proportion so as to show the antero-dorsal arms. 



Figs. 4-11. Transverse sections through fore-head {i. e. at right angles to its longer axis), 

 in planes indicated by side-lines in figs. 1-8. X 1245. 



Fig. 23. Vertical section through fore-head, showing salivary pump and maxillary stylets. 

 X 300. 



Plate 25. 



Figs. 12-14. Continuation of the same series of transverse sections. 



15-22. Transverse sections through fore-head in planes indicated by side-lines in 

 figs. 1-3. Continuation of same series. X 450. 

 Fig. 24. (a) Extremity of compound maxillary stylet, showing two canals, x 1250. 

 (b) Extremity of mandible, x 1250. 

 25. Longitudinal section, almost median, showing gustatory organ and its relation to 

 perforated epipharynx. Stained with hajmatoxyliu and orange G. X 450. The 

 section is not quite median. 



