486 THE HiEMATOZOA OF AUSTRALIAN REPTILIA, II., 



H^MOGREGARINA (KaRYOLYSUS) BANCROFTI, n.Sp. 



(Plate XV., figs. 16-24.) 



Dr. Bancroft forwarded some blood-smears from two snakes, 

 Pseudechis mortonp.nsis De Vis, and P. anstralis Gray, killed in 

 the Burnett River district in January and March respectively. 

 These, on examination, were seen to be parasitised by a hyeinogre. 

 gariiie, which differs considerably from those previously seen by 

 us. We have accordingly described it as a new form, associating 

 with it the name of Dr. Bancroft, who has rendered us such 

 generous assistance in regard to material. 



The parasite i-esembles H. megalocystis (Gilruth, Sweet, 

 and Dodd, 1910, p. 234), from Python variegafii.^, in its effect 

 on the host-cell. There is very marked increase in the size 

 of the latter, its protoplasm becoming very thin and dehaemo- 

 globinised. Not infrequently, the cell-outlines become so 

 faint as to be unrecognisable. Sometimes the stroma (or por- 

 tion of it) of the host-cell remains surrounding the parasite 

 and the host-nucleus, the latter being only slightly displaced 

 lateral!}'. Normal cells are from 15-19 /x in length x 1 0- 1 1 /x 

 in breadth, whilst infected cells may reach 31-5 x l7-5/x. The 

 parasite lies at aboxit the middle of the erythrocyte, with its 

 concavity partly surrounding the host-nucleus, which does 

 not seem to be detrimentally affected, though the stroma 

 becomes profoundly altered. The amount of alteration is not 

 dependent on the size of the hsematozoon contained within 

 the cell. No definite capsule enclosing the parasite was recog- 

 nised, except in one case, where it was seen to invest the 

 organism very closely. 



The hsemogregarines are relatively small, measuring from 

 10-17 /A long, by about 3//. broad, and of a fairly regular 

 form and even breadth, as will be seen from the figures. A 

 few broader forms were seen, these measuring about 5 //. 

 in width. The ends were usually similar. The nvicleus was 

 sometimes near one end, at other times it was centrally situ- 

 ated. The protoplasm of the parasite was very faintly 

 stained, and, at times, large vacuoles were seen. 



