On tlie slrucliuc of llie neiiliiiili.i i>f Sticlio>tc'niinn. 275 



Explanation of Plate. 



Plate 23. 



All the figures, except Fig. 9, have been drawn with the aid of 

 the camera Incida, with the magnification afforded by the homogeneous 

 immersion '/jg of Zeiss. And all, with the one exception noted, were 

 made from preparations fixed in aqueous solution of corrosive sublimate, 

 and stained with Delafield's haematoxylin, followed by alum-carmine. 



The following abbreviations have been employed: 



A anterior. Epi body epithelium, 



Amp ampulla of excretory duct, Ex. P excretory pore, 



B terminal bulb, L left side, 



B. C bod}^ cavity, L. M longitudinal musculature, 

 Bni basal membrane, Lo2 cuticular almond, 



C cells of terminal bulb, N nucleus, 



Cnv cavity of terminal bulb, Neph main duct of nephridium. 



Cil cilia, P posterior end, 



C. M circular musculature, P. S proboscideal sheath, 

 Cu cutis, B right side, 



Cut cuticula, X granular mass in the cavity 



d ductule, of the bulb. 



Fig. 1. Section through terminal bulb, ductule, and main duct of 

 a nephridium. Oc. 2. 



Fig. 2. Section through a terminal bulb. Oc. 4, tube extended. 

 Fig. 3, Section through a terminal bulb , the section cutting the 

 latter at right angles to its broadest side. Oc. 4, tube extended. 

 Fig. 4. Section through terminal bulb. Oc. 4, tube extended. 

 Fig. 5. Longitudinal section of a nephridial main duct. Oc. 4. 



Fig. 6. Section through two fused terminal bulbs. Oc. 4, tube 

 extended. 



