larvae of Sph. oligorchis has a ciliary covering of the same type as 

 Neopolystoma palpebrae which the author was unable to find. The larvae 

 ennerge from the egg with a greater or lesser development of the attach- 

 ing armature and of its separate parts (Fig. 219), but they already have the 



Fig. 217. Sphyranura oligorchis 

 Alvey, larva which emerge from 

 the egg on the 27th day of develop- 

 ment. Magnified 188 times. 

 (According to Alvey, 1936). 



Fig. 218, Sphyranura oligorchis . 

 the subsequent stage of develop- 

 ment of the larva. Magnified 215 

 times. (According to Alvey, 1936). 



same relations of the disc and armature as the grown forms , i. e. , 

 edge hooks of the final size, 2 middle hooks and 2 suckers. The 

 middle hooks and both suckers do not have the final form or dimensions 

 and grow for a long period of time. The sizes of the edge hooks of the 

 larva are about 0. 25 mm, the length of the middle hooks is about 0. Oil 

 mm^. The internal organization of the larva was poorly studied by the 



1 



Alvey erroneously wrote 0. 25 and 0. II mm; we verified this from 

 his figures. 



author. It is known that there is a more or less well-developed pharynx 

 and a small circular intestine. The eyes are absent just as among adult 

 worms. The excretory bladders lie along the sides of the intestine and 

 are easily noticeable in the larva. The development of the sex system 

 takes place, according to Alvey, in about 2 months. 



208 



