70 • W. N. F. WOODLAND 



in optical section the type of larva found in large numbers 

 in the third limb of the uterus in a worm more than 130 mm. 

 long (the worm which was in course of boring its way through 

 the fish body : vide PL 3, tig. 3). In these larvae (which were 

 about 200 microns in length — twice the length of other mature 

 larvae observed by me), whether mounted whole or in section, 

 I found it difficult to detect for certain the central group of 

 gland-cells which is so distinctly figured by Salensky (vide his 

 tig, 34) and Janicki (vide his fig. 16) and which I have seen 

 clearly in sections of younger larvae, the probable reason 

 being that the gland-cells are much distended and full of 

 unstained secretion : it is difficult to suppose that the gland- 

 cells have disappeared at this stage. The anterior end of the 

 larva (the end opposite the booklets) is usually drawn out 

 somewhat and probably carries the fine ducts of the gland- 

 cells. The larva at this stage has usually escaped from its shell 

 and has secreted a thin but definite cuticle, outside which lies 

 the remains of the investing membrane. I could detect no 

 trace of ciliation on any part of the surface. 



The foregoing facts were, as I have stated, observed by me 

 in specimens of A . p a r a g o n o p o r a ranging from 30 mm. 

 to 130+?mm. in length and require no particular comment. 

 In one of my two largest specimens of this worm (both 280 mm. 

 long when living and uncontracted), however, I found, both in 

 horizontal and vertical longitudinal sections, in portions of the 

 body mounted whole and in macerated preparations of the 

 body, two types of products in the uterus (all three limbs of 

 which apparently contained the same or similar products) : 

 (1) oval flattened larvae (PI. 4, figs. 38, 39) with typical booklets 

 and possibly with gland-cells (though I could not observe them 

 even in sections ; however, large spheres, not shown in PI. 4, figs. 

 3, 8, could occasionally be distinguished deep in the substance) 

 and only as long as the larvae liberated from worms 100 mm. 

 long, i. e. half the length of the larvae represented by PI. 4, 

 fig. 35 ^ (though the booklets were the same size in both) 



1 I am unable to say whether the larvae of PI. 4, tig. 35 are abnormally 

 large (since they were only found in a single worm) or whether the flat 



