BY T. HARVEY JOHNSTON. 407 



HiEMOGREGARINA CLELANDI, 11. sp. 



(Plate XXXV., figs. 1-12.) 



Dr. J. B. Cleland. while in Perth, took some blood -films from 

 the coimiioii West Australian tortoise, Clielodina oblongaC^^) Gray, 

 the erythrocytes of which, on being stained with Giemsa, were 

 seen to be rather lieavily infected with a relatively broad 

 lijemogregarine. 



Tlie sporonts were apparently of two types, which may repre- 

 sent some sexual differentiation. Jn the one type the jjarasites 

 were lightly staining, and showed a number of structures 

 resembling vacuoles. Sometimes there was only one, this being 

 situated raostl}^ at one end; sometimes there were one, two, or 

 more at each end, their number, position, size, and shape being 

 variable. Occasionally they were near the centre. The other 

 forms were generally larger, more deeply staining, and non- 

 vacuolated. Do the former represent male sporonts, and the 

 latter female 1 These parasites ranged from 11 b}' 5 /^t to 13 by 

 7 fjL, the uninfected host-cells being from 18-20 /m long, by 10-12 /x 

 broad; whilst infected host-cells were considerably larger, reach- 

 ing from 20-24/i in length, by from 10-13-5 /^t in width. 



There were many young stages represented, some of the para- 

 sites being only a little longer than the host-nucleus (7 jj. by 4 /i). 

 They were not encapsuled, and were usually vacuolated. The 

 positions which they occupied in their hosts were very varied. 

 Some lay transversely, with the concavity facing the host-nucleus 

 in some cases, and remote from it in others. Sometimes they 

 were placed longitudinally, either laterally, or along the median 

 line of the host. The most usual position was somewhat oblique 

 from the longitudinal axis of the erythrocyte. Even in the case 

 of adult forms, it was quite exceptional to see any instances 

 where the parasite was occupying the position usually taken up 

 by haeniogregarines, i.e., longitudinally between the nucleus 

 (usually somewhat displaced laterally), and one side. Almost 

 invariably was the host-nucleus displaced even by 3'oung forms. 

 Another fact worth mentioning is that the displacement was in 



