104 



(7). Protoplasm like (6) ; nucleus pale-red, rounder ; 



melanin as mass of several grains at one end, as 4 



scattered grains at other, and as 2 scattered ones 



near nucleus. 

 (8). Protoplasm deep-blue, vacuolated; nucleus rounded, 



small, purplish. 



Halteridium, sp. from Ptilotis plumula, Gould (Fam. 



Meliphagidcz) . 



Plate xxvi., figs. 16-22. 



Halteridia were found in a honey-eater, Ptilotis plumula y 

 shot at Perth, Western Australia, in August, 1909. As far 

 as we know, the finding of a blood parasite in native birds 

 from that State is now recorded for the first time. As the- 

 various European birds which have been introduced into the 

 Eastern States of Australia (the sparrow, goldfinch, blackbird, 

 starling, thrush, English skylark, etc.) do not so far exist in 

 Western Australia, it shows that Halteridia were present in 

 Australian birds before the introduction of species from else- 

 where. 



Most of the parasites were immature forms. In the only 

 large halter form met with, the nucleus of the host cell was 

 pushed a little aside. We can detect no definite differences 

 (unless in a smaller amount of pigment) between this para- 

 site and the Halteridium found in Ptilotis chrysops in Sydney 

 district, though the two host birds are separated by a distance 

 of about 2,000 miles. 



The descriptions of nine successive specimens afterwards 

 arranged in order are as follow : — 



Host's red cells, 10*5 /x. x 5'5 jut. ; nucleus, 7*2 /x. x 2 \i. 



(1). Very minute form; clear; as yet no pigment. 



(2). Pale-coloured; 3*6 p. in size; three small melanin 



grains. 

 (3). About same size as (2); at one end of host cell; no 



pigment. 

 (4). A little larger; at one end; small granule of 



melanin. 

 (5). At one end; 6"3 /x. long; edge of parasite well 



defined, centre clear, 2 granules in centre. 

 (6). Half -grown ; clear ; small pigment granules along sid& 



towards host's nucleus and several in middle. 

 (7) . Half-grown ; pale ; melanin along edge next host's 



nucleus (? artefact). 

 (8). Length of host's nucleus, but thinner; well stained; 



several melanin granules all at one end. 



