258 RECOUPS OP I'll K AUSTRALIAN MUSEUM. 



seen nearer this end as a dense deeplystaining body, having about 

 the .same width as the animal. The size of the parasite at this 

 staye is from nine ll by 18 ^ to thirteen ll by 2-4 ll, the nucleus 

 being about two ll long. One or two specimens were only as long 

 as the nucleus of the host (PI. lxxii., fig. 23). The corpuscles were 

 not much affected at this stage, their nuclei remaining central. 



The yuung forms increase in bulk and become encapsuled as 

 spoionts, the ultimate host being probably a tick since the->e 

 ectoparasites are frequent on snakes. Tn the encapsuled parasite 

 the posterior end becomes bent round so as to he close to the cell 

 (P! lxxii., fig. 12, 14). This "tail" is very short and is not distin- 

 guishable in most of the specimens. The nucleus is either median 

 or approaches the anterior end, and is now relatively larger and less 

 dense, vacuoles appearing to separate its chromatin fibres. The 

 cytoplasm has a number of deeply-staining granules occurring at 

 each end of the cell. The capsule is hard to make oUt unless the 

 tail is well marked (PI. lxxii., fig. 14, 21). 



The sporonts vary from twelve ll by 3G ll to 105 ll by 2*4 ll, 

 the average being 108 ll by three ll. They are thus very much 

 smaller than //. shattocki. 



There are also large forms present. These resemble schizonts 

 (i.e. , the stage which undergoes fission to produce merozoites) in 

 most of their characters but do not possess the large refracting 

 granules in the cytoplasm. These cells are reniform and broad, 

 with a fairly distinct capsule. The nucleus is round, large and 

 approximately medium. The size of the latter is from three to 

 four fx long by 2 5 to three /t broad, the parasite varying from 

 13 5 ll bv 4 - 5 fi to eleven ll by four ll. Perhaps these are only 

 large sporonts in which the "tail" is not visible (PI. lxxii., 

 figs. 19,21). 



The host cell does not seem to be affected to any degree by the 

 organism, though the nucleus is usually displaced, sometimes 

 actually lying against the periphery (PI. lxxii, fig. 21). The only 

 ones of both host and parasite are parallel in nearly every in- 

 stance. Exceptions are sketched in PI. lxxii, tigs. 10, 16. The 

 distortion of the host cell shown in some of the figures was, no 

 doubt, artificially produced in making the film. I propose for this 

 sporozoan the name, Ifmmogregarina amethystina, borrowing 

 the specific name of the host. Its nearest ally seems to be //. 

 pococki, Sambon and Seligmann, from the erythrocytes of the 

 Indian python, Python molorus, I. inn. 



The range of Python aoiethysliua, Schn., is from the Moluccas 

 and Timor, through New Guinea to New Britain and New Ireland 

 and southerly to Northern Queensland. 



