﻿PARASITES III 



is found attached to the intestinal mucosa of Milvus 

 bidentatus. 



Nematoda. — The roundworms (Nematoda) so 

 far described from snakes belong to the fami- 

 lies Ascaridae, Strongylidse, Trichotrachelidae, and 

 Filariidae. Some of the genera belonging to these 

 families, such as Cucullanus, Neniatoxys^ Oxysoma, 

 are as yet represented by a single species in a single 

 host ; others, . such as A scaris, Polydelphis, Heiercikis, 

 StrongyluSj DiaphanocephaluSf Pkysaloptera, Tricho- 

 soma, number already several species more or less 

 widely distributed. 



Eelworm infection (ascariasis) is very common in 

 snakes, and not infrequently the infection is a heavy 

 one; Sambon twice found over fifty specimens 

 of Polydelphis in Puff-adders {Bitis arietans). This 

 investigator has shown that the snake eelworms 

 undergo an encysted stage of development within 

 the body cavity of their hosts before migrating into 

 the intestinal lumen for the purpose of fertilization 

 and oviposition. Thus, Redi was quite right in 

 considering the immature, encysted forms found in 

 one of the livers of his double-headed Asp as 

 belonging to the same species of eelworm (Ascaris 

 cephaloptera) as that which the snake harboured in 

 its intestine. 



Professor A. Railliet, whilst examining specimens 

 of Polydelphis which had been preserved for nearly 

 two months in a 3 per cent, solution of formalin, 



