406 ON SOME HiEMOGREGAUINES FROM AUSTRALIAN REPTILES, 



H.EMOGREGARINA PSEUDECHIS, n.sp. 



(Plate XXXV., figs.13-20.) 



A black snake, Pseudechys porpht/riacus Shaw, obtained near 

 Sydney, was found to be parasitised by heeraogregarines which 

 were not by any means abundant. 



The host-cells were about 15 /x by 10 /x, with nuclei 7 5 /x by 

 4 /x; whilst the parasites were generally about 14 /x by 3-b fx. In 

 addition to these typical hsemogregarines, there were present a 

 number of very small parasites with a definite non-amoeboid 

 shape which was rounded, elongate or pyriform. These measured 

 3 or 4/x long by I'd fi broad, and, no doubt, represented very 

 early stages. If we except these very small forms, the youngest 

 hsemogregarines appeared as large, slightly club-shaped bodies, 

 with a thicker, rounded, anterior end tapering very gradually 

 towards the blunt, and slightly curved, posterior extremity. 

 These were from 12 to 14 /x long, by from 3 to 4 ^lx wide. A few 

 specimens possessed a swelling on the concave side in the region 

 of the nucleus. Their nuclei were broad and band-like, and were 

 generally placed towards one or other end. The capsules were 

 very deKcate, and, as a rule, were not easily distinguishable. 

 The only effect produced on the host-cell by the presence of the 

 parasite was the displacement of the nucleus to the edge of the 

 erythrocyte. 



Adult forms were less bulky, and showed delicate but very 

 distinct capsules which were not closel}^ adherent to the parasites, 

 especially on the concave side. Their sizes were 13 or 14/x, by 

 about 4/x. In a few cases the posterior end was bent round in a 

 manner similar to that mentioned in Jfl. morelice. The central 

 portion was bulged out on the inner side, the nucleus generally 

 lying just anterior to it. As a rule, the concavity of the animal 

 faced the host-nucleus, the latter being displaced laterally, though, 

 in some instances, the displacement was towards one end of the 

 red cell. No distortion of the host-cell was observed. 



The generic name of the host has been borrowed as a specific 

 na.me for the parasite. A type-slide has been presented to the 

 Australian Museum, Sydney. 



