on a new reptilian cestode. 103 



Explanation of Plate and Diagram. 

 Plate III — Haemocystidium chelodinae. Microphotograph of 

 portion of film, showing an erythrocyte (in the centre of 

 the field) containing a parasite. The vacuoles and pigment 

 are visible. 



Diagram I — Haemocystidium chelodinae. 

 Fig. 1, young parasite. 

 Fig. 2, elongated form. 



Figs. 3, 4, 5, 6, 8, 10, 11, more usual forms; commonly some- 

 what amoeboid. 

 Fig. 7, non vacuolated form. 

 Fig. 9, distinctly amoeboid parasite. 

 Fig. 12, parasite protruding from injured host cell. 

 All the above were drawn with a camera lucida. 



On a NEW REPTILIAN CESTODE. 



By T. Harvey Johnston, m.a., b.sc, Assistant Government 



Microbiologist. 



(From the Bureau of Microbiology, Sydney.) 



[With Plate IV.] 



[Communicated by C. Hedlby.] 



[Read before the Royal Society of N. S. Wales, July 7, 1909.'} 



A narrow, thread-like, rather delicate tapeworm occurs in 

 the alimentary tract of the common Monitor, Varanus 

 varius, Shaw. In a specimen of this lizard which I obtained 

 near Bathurst, N.S. Wales, these parasites were present 

 throughout almost the whole length of the intestine, being 

 numerous in the duodenum. Their occurrence in the upper 

 part of the rectum is worth noting, as this is not a usual 

 place for cestodes. The length of the cestode is from 27 

 to 30 millimetres, probably more in fully mature specimens; 



