336 ON SOME TREMATODK PARASITES OF AUSTRALIAN FROGS, 



0-044 mm., thick-shelled, with, at the narrower end, a much 

 thickened patch of shell, that is often developed into a blunt 

 process. 



Host, Hyla citropus, in the duodenum. 



Type-specimen in the Australian Museum, No. W.342. 



In November last, I collected at the Lodden River, near 

 Bulli, N.S.W., two specimens of Hyla citro'pus, a rather rare 

 frog, and from the intestine of one of these, I obtained two 

 small flukes, described above. One of the two was smaller 

 than the other, and hardly sexually mature. 



Genus Mesoccelium Odhn. 



Table for dtterminalion of the !^pecies. 



Integument densely spiny; ratio of oral to ventral sucker not greater 

 than 3 : 2. 



Testes triangular; ovary triangular, behind left testis; yolk-glands extend- 

 ing backwards to behind the ovary; eggs 040 x "025 mm 



M. sociale. 



Testes oval or rounded; ovary oval or rounded, behiiid the right testis; 

 yolk-glands not extending backwards beyond the ovary; eggs 004 x 

 "025 mm M. mesemhrinum. 



Integument smooth or very little spiny; ratio of oral to ventral sucker 

 greater than 3 : 2. 



Testes oval; ovary spherical, latero-median; ynlk-glands not extending 

 backwards behind ovar}'; eggs 047 x "029 mm M. megaloon. 



Testes polyhedral; ovary oval, behind right testis; yolk-glands extending 

 backwards behind ovary; eggs 0'044 x 0"028 mm M. oligoon. 



Amongst known distomes, it is to Brachycalivm crassicolle 

 R., that the four species of this genus appear to be most 

 closely related, and I think they may be looked vipon as the 

 Asiatic and Australian representatives of that worm. I place 

 the genus in the subfamily Brachycoeliinse, in which Looss 

 (50) places Phaneropsolus, Lecithodendrium, Pyenoporus, 

 and Brachyc(Hiiim. Pratt, in his Synopsis of American In- 

 vertebrates (75) also places the same genera in this subfamily. 

 In the characters of the integument, the position of the geni- 



