EXPLANATION OF PLATE XXXVI. 



Tvphloperipatus willianisoni ^ Kemp. 



Male Reproductive Organs. 



Fig. I. — The entire system seen from above, displayed semidiagrammati- 

 cally, magnified about 7 times. In order to show the 

 various parts clearly a certain amount of lateral displace- 

 ment has been necessary. The testes, separated in the 

 figure, run together for the greater part of their length; the 

 right seminal vesicle slightly overlaps its fellow and the 

 vasa deferentia form an intricate mass in the hinder part of 

 the body. 



The dotted lines in the background indicate the position, in 

 relation to the reproductive organs, of the body-wall and 

 legs, the latter being numbered (V-XIX) in roman numerals. 

 The thick-walled portions of the vasa deferentia are distin- 

 guished by oblique hatching. 



The position of the sections shown on either side is indicated 

 by horizontal lines and reference letters A-F. 



A. vSection through one of the thick-walled portions of 



the vas deferens. 



B. Section through one of the thin-walled portions of 



the same duct. 



C. ^ Sections through the common duct. In C and D 



D. I sections of partially formed spermatophores are 



E. f show a. E and F pass through the ductus ejacula- 



F. J torius. 



,, 2. — The anterior loop of the common duct of the same specimen 

 indicated by dotted lines, with the spermatic mass shown 

 diagrammatically in optical section. It will be noticed that 

 the walls are thickened at various points and that the mass 

 comprises three partially formed spermatophores. The posi- 

 tion of the sections shown to the right is indicated by 

 horizontal lines and reference letters G-J. 



G. Section through the thick-walled portion joining two 



partially formed spermatophores The lumen al- 

 most obliterated and characteristically star-shaped. 



H Section through the main sac of a spermatophore : 

 the inner wall irregularly fluted and surrounded by 

 a smooth chitinous coat. 



J. Section through the chitinous cap. 



Reference Letters. 



c.d., common duct. m.a.g., male accessory gland. 



d.e , ductus ejaculatorius. n.c, nerve cord. 



/.^ , left testis. r.. rectum. 



l.v.d., left vas deferens r.t.. right testis. 



l.v,&., left vesicula seniinalis. r.v.d., right vas deferens. 

 r.v.s., right vesicula seminalis. 



