216 ON AUSTRALIAN ENTOZOA, 



shaped head which is figured (much enlarged) on plate I., 

 No. 15. 



I have taken great pains to ascertain how far 1 am justified 

 in classing so many different-headed cestoid colonies as one 

 species, but as all contain the same kind of ova, (circular 

 bodies enclosing a granular round central capsule without hooks), 



1 must be correct in my observation. 



Besides no other cestoid examined was in any way tuberculated. 

 One species closely resembles the present one, and broken pieces 

 of it gave much trouble when classifying the specimens obtained 

 during a day's collecting, but as soon as the test was applied, 

 the different shaped ova proved the fragments to be of 

 another form and not those of Tcenia tuberculata. I mentioned 

 already that the principal host to this tape-worm is the White- 

 eyed Duck (Nyroca mtstralis). 



Many specimens are in the collection of the Australian 

 Museum. 



TAENIA NOViE-HOLLANDIiB. 



(Plate I., figs. 1, la, lb, Ic, Id, le, 2, 3, and 18. 

 Plate III., figs. 28 and 28a). 



This species resembles the one previously described and is 

 almost as variable, with regard to the shape of the anterior 

 portion of the colony at least. 



Specimens with short tubercular or thin thread-like processes 

 surmounting the broader and thicker " body " or " colony " are 

 common, (figs. 16, Id, and 18 of Plate I.), others occur in which 

 four indistinct suckers can be traced on the most anterior of the 

 segments ; others again resemble the figure given on Plate III., 

 No. 28 and 28a, they show four round disks and a retracted 

 proboscis, but all produce the same kind of ova. (Plate 1., figs. 



2 and 3.) The most common form consists of an oval 

 disk enclosing a tube with round caps at each end and four 

 hooks in the middle. Another ovum occui's with the ends more 

 arched, and the sides bulged out like a cask, (probably a more 

 advanced state) and a third, perhaps an earlier stage, has a double 

 cap on one extremity of the tube (Plate I., fig. Ic.) The last 



