120 EXPLANATION OF PLATES VIII. AND IX. 



salivary duct to the upper part of the hind wall of the pharynx ; n, lower 

 part of the salivary duct ; o, upper part of the same. 



Fig. 22. — Basal portion of external and distal portion of some of the 

 internal mouth-parts of Stc/moxys calcitrans, L., 6 , drawn by transmitted 

 light ; X 54 : a, labrum ; b, basal part of its left apodeme ; c, basal part of 

 the hypopharynx ; d, base of hypopharynx and of the plate in the groove 

 of the labrum ; e, small part of the base of the plate in the labial groove ; 

 /, lower part of the pharynx itself ; g, tube between the pharynx itself and 

 labrum-hypopharynx ; 7j, lower part of the salivary duct (the wall is thick); 

 i, upper part of the same duct (the wall is thin, with linear circular 

 thickenings) ; k, dilatation of the same duct ; m, terminal part of its left 

 muscle. 



Copenhagen, 

 August 26, 1902. 



