256 



H.EMOGREIiARIXA (LaXKESTERELLa) RYLiM, n.Sp. 



(Pigs. 11-22.) 

 The red blood corpuscles of tlie common " Green Tree- 

 frog " of Australia, Hi/lu cacnilctt, White, appear to be 

 very frequently parasitised by a haemoprotozoon belonging 

 to the Haemogregarinidse. This sporozoon has been 

 detected in three out of five specimens of this species 

 examined by us. Although we have sought for haematozoa 

 in the allied "Golden Frog" Hyla aurea, Lesson (sixteen 

 specimens) we have not yet succeeded in finding any. The 

 infected frogs came from the Sydney district, but the 

 species ranges over the whole of the warmer portions of 



The parasites showed the typical features of a batrachian 

 Haemogregarimi (Lankesterella). They did not vary much 

 in size, the length being about 0*009 to 0*011 mm., with a 

 maximum breadth of 0'003 mm., though on one occasion a 

 form having a breadth of 0*005 mm. was noticed. The 

 parasites were generally much thinner varying from 0*0016 

 to 0*0025 mm. Many of the narrower forms were immature. 

 The usual shape of the parasite in the red cell was that of 

 an open crescent, its concavity most often facing the host- 

 nucleus, but occasionally turned from it. In parasites 

 wliii-h had escaped from their hosts, the two sides were 

 however, almost alike. In the centre of the concavity 

 there was often present a more or less extensive bulging. 

 In no case did the parasite possess a tail. 



The protoplasm of the parasite proper stained a pale 

 bluish colour. It was usually studded with fine reddish 

 granules. The nuclear band was often nearer one end than 

 the other, and sometimes in these cases the part of the 

 parasite beyond the nucleus was non-granular, while the 

 rest of the parasite was distinctly granular. In a number 

 of cases the characteristic reticulate nucleus was not dis- 



