52 ENTOZO.A OF MONOTKEMATA, ETC., U., 



lapped by the proglottis immediately anterior to it. The 

 posterior third of each segment (i.e., the overlapping portion) 

 in this region is very thin. The ratio of length (0178 mm.) 

 to breadth is 1 : 3 (Fig. 4). This is followed by a region in 

 which there is an increase in size, and in the degree of 

 development of the segments, all the genitalia being present, 

 though small and not yet functional. The edge presents a 

 serrated appearance, as the margins project considerably. 

 The amount of overlap is small, amounting to about one-fifth 

 of the length. The ratio of length (0-32 mm.) to breadth 

 (0-84 mm.) is about 2:5 (Fig. 5). Segments which have 

 reached sexual maturity, have almost the same form (Fig. 6), 

 except that they are slightly longer, reaching 0-42 mm., and 

 are much less overlapped by the preceding proglottis. Ripe 

 segments have about the same length as the last-mentioned, 

 but are much broader, being 1-62 mm. in width, the ratio 

 thus being 1:4. Similar variations in the entire strobila 

 were seen in fragments of another specimen belonging to the 

 same species. 



Having only microscopic preparations available, no sections 

 were made, and consequently details regarding the body- wall, 

 muscvilature, etc., cannot be given. Throughout the greater 

 part of the cortex of the strobila, there are numerous large, 

 calcareous bodies of an elliptical form, measuring about 

 0012 by 0-0075 mm. They are less abundant in the anterior 

 portion of the worm. 



The nervous system could not be followed with any cer- 

 tainty. There seem to be three nerves on each side, a main 

 strand and two accessory nerves, the former apparently lying 

 dorsally to the genital canals. 



The excretory vessels lie at some distance inwards from the 

 lateral margins of the segments, their course being fairly 

 straight. The ventral pair are large, the lumen of eacli 

 being about 0043 mm., the dorsal trunks being very much 

 narrower, their diameter reaching only 0010 mm. The 



