On a CESTODE from DACELO GIG AS, BODD. 



(Communication from the Government Bureau of Microbiology, 



Sydney.) 



By T. Barvby Johnston, M.A., B.Sc, Parasitologist, Bureau 

 of Microbiology, Sydney; Hon. Zoologist, Australian 

 Museum. 



(Plate Ixx.). 



My friend, Mr. S. J. Johnston, of the Biology Department, 

 SydLey University, recently handed over to me a collection 

 of Entozoa, mainly Cestoda, collected by himself and Professor 

 J. P. Hill. The specimens now to be described were obtained 

 from the stomach of a Liughing Jackass (Dacelo gigas, Bodd.) 

 at Gloucester, New South Wales. Tapeworms do not commonly 

 occur in the stomach, most of them preferring the alkaline 

 conditions and abundant food supply present in the duodenum. 



The largest specimen is about one hundred and twenty milli- 

 metres long and consists of approximately four hundred and 

 twenty proglottids. Just behind the scolex, the breadth is - 3 

 mm., gradually increasing to two mm. at about one third of the 

 total length of the strobila, the remaining segments being prac- 

 tically uniform (2*5 mm.) In flattened and mounted specimens 

 the dimensions are increased. 



A neck is hardly recognisable, as constrictions appear margin- 

 ally immediately behind the scolex and segmentation is distinctly 

 seen in the strobila one millimetre from the head. There is no 

 marked constriction between the scolex and the strobila. 



There is very little overlapping of the anterior edges of 

 segments by the posterior parts of those in front of them, nor is 

 there much lateral projection. Excepting in the anterior fifth 

 or quarter of the chain, there is not much difference in the size 

 of the segments, the ripe and the sexually mature proglottids 

 measuring about two to two and a-half millimetres in width by 

 07 to 08 mi), in breadth. They are thus from three to four 

 times as broad as long. Those near the scolex are 0'4 mm. long 

 by 03 mm. broad, the succeeding segments gradually broadening. 



