A NEW MELANIN-PRODUCING HAEMATOZOON. 101 



in others they were absent. The melanin was sometimes 

 in angular granules, sometimes in short rods; it was 

 scattered irregularly as fine granules, confined to one half 

 of the parasite, or grouped into little masses often towards 

 the centre. 



The erythrocytes of this tortoise were from 17 to 18*5 

 micra long by from 10 to 12 broad, the nuclei being about 

 5 by 3*5 micra. The parasites varied from 4 by 3 micra to 

 12 by 7. Their relative proportions and size are indicated 

 in the figures. The average diameter of the large rounded 

 forms was about 9 micra, whilst those possessing a reniform 

 shape measured about 6 micra across the middle and reached 

 a length of 12 micra. Only two specimens under 8 micra 

 in their greatest length were seen. The vacuoles had a 

 definite, rounded constant form, the diameter being about 

 1 micron. Their position was variable as the figures show. 



We propose for this organism the name oiHaemocystidium 

 (Plasmodium) chelodinae. It differs from H. (Plasmodium) 

 metchnikovi in the granules being more numerous and 

 irregularly scattered, in the average size being a little 

 larger, and in forms being present with large melanin 

 granules and deep staining protoplasm, which agree with 

 neither Simond's male nor female gametocytes. 



The type slide has been presented to the Australian 

 Museum and co-types have been retained by the Bureau. 



Addendum. — In the Third Report of the Wellcome 

 Research Laboratories of Khartoum, 1908 (1909), whose 

 prospectus with abstracts has just reached us, we find that 

 Dr. Wenyon has described three new species of melanin 

 producing haematozoa from Soudanese reptiles, viz., Plas- 

 modium mabuiae from a lizard, Haemoproteus agamae also 

 from a lizard, and Haemocystidium najae from the Spitting 

 Cobra (Naja nigricollis). We have not yet received the 

 full report, and are therefore unable to compare these 

 species with ours. 



