no INTRODUCTION 



terns, first described, in 1861, by De Filippi. In 

 igio Sambon included in this genus other similarly 

 structured Linguatulids from crocodiles, monitors, 

 and snakes. 



The genus Raillietiella was established by Sambon 

 in 1910 for a Linguatulid {Raillietiella boidengeri) of 

 the African Puff-adders (Bitis arietans, B. gabonica). 

 Amongst the characters of this genus is one of 

 great structural and phylogenetic importance — viz., 

 the position of the female sexual orifice at the 

 anterior end of the abdomen, whilst in the other 

 known genera it is at the posterior extremity. 



According to Prowazek, Sambon, and Laveran, the 

 Ophidian Linguatulids, which live as blood-suckers 

 in the air-passages of their hosts, are able to 

 foster and transmit the haemogregarines of these 

 hosts. 



Acanthocephala. — The early encysted stages of 

 several species of Thorn-headed worms (Acantho- 

 cephala), belonging to the family Echinorhynchidcu, 

 have been reported from snakes belonging to very 

 different genera, such as Boa, Tropidonotus, Zamenis, 

 Drymobius, Xenodon, Dipsadomorphus, Oxyrhopus, 

 Erythrolamprus, Diemenia, Naja, Elaps, Vipera, 

 Lachesis. Their further development probably 

 occurs in ophiophagous birds. Thus, Echinorhynchus 

 oligacanthoides, Rud., the immature stages of which 

 occur encapsuled within the body cavity of Lachesis 

 lanceolatus and other neotropical snakes, when adult 



