58 W. N. F. WOODLAND 



internal to the row of vitellaria on each side of the body. 

 In all four species the uterus opens at the extreme anterior 

 end on the left side at the base of the protruded proboscis 

 (PI. 4, fig. 16).^ Some small differences may exist in the 

 arrangement of the ducts adjacent to the ovary in the different 

 species, but, judging from the (in some cases rather doubtful) 

 figures, the general arrangement found in A . p a r a g o n o p o r a 

 is found in all. I may add that the ventral position of the 

 vitelline ducts relative to the uterus shown in Hein's fig. 14 

 (correctly indicated as dorsal in his fig. 13 however), and 

 relative to the sperm ducts and the ovary shown in Janicki's 

 figs. 5 and 6, is probably an error in both cases — in both cases 

 the vitelline ducts should be shown as dorsal to these organs. 



{c) The P r 1) s c i s : its Musculature and 

 Connexions. 



When A. paragonopora is removed from the body- 

 cavity of a freshly opened fish and placed on a slide in body- 

 cavity fluid, the extreme anterior end of the worm is sometimes 

 seen to be protruded into a narrow process which moves 

 vigorously from side to side in groping movements (Pis. 3, 4, 

 figs. 1, k, and 15, a). More usually, however, this protrusible 

 portion of the anterior end is not visible, it having been tightly 

 retracted inside the body-contour (PI. 4, fig. 15,6). This pro- 

 trusible portion of the anterior extremity I shall term the 

 ' proboscis ', and, as will be seen, it is essentially an introvert 

 in structure. In three or four of my specimens the proboscis 

 chanced to be preserved in a protruded condition (PI. 4, fig. 16), 

 while in all the others the proboscis was retracted (PL 4, fig. 17). 

 From these figs. 16 and 17 it will be seen that the proboscis 

 essentially consists of a thickening of the wall at the extreme 



parenchjnna ' in A. magna, but his figure shows that the arrangement 

 of the testes is linear, as in A. liguloidea and A. paragonopora. 

 ^ I am unable to understand why Southwell (8, p. 327) supposes that 

 A. foliacea has no uterine opening 'at the base of the small anterior 

 end of the worm ', 



