BY S. J. JOHNSTON. 331 



Type-specimen iu the Australian Museum, No. W.341. 



In the duodenum of our green ti-ee-frog, Hyla ccerulea, 1 

 found specimens of this fluke three times, getting four speci- 

 mens from one frog in the winter, 85 and 7 from two others 

 in the summer, making a total of 96 flukes, 25 of which were 

 cut into sections, and the remainder mounted as whole- 

 mounts. Those found in the first case, were somewhat larger 

 than the others, their length varying from 244 to 3-7 mm., 

 their breadth 0-89-1.6 mm., average length 3. 14 mm., and 

 breadth 11 9 mm., while the average measurements of the 

 others are 2-035 mm. long, by 0-644 mm. broad. The suckers, 

 in the larger specimens, are naturally rather larger than in 

 the smaller ones, the oral sucker being 0-2934 mm. in dia- 

 meter, the ventral sucker 0-1956 mm., the ratio of oral to 

 ventral being 1-5 :1. About the same ratio between the suck- 

 ers holds for the smaller specimens, and, in the rest of their 

 organisation, they are practically identical with the larger. 

 The shape of the living worms was fusiform, both ends being 

 about equally pointed ; but the anterior end is much more 

 mobile, and wlien the worm is killed, generally contracts 

 more, so that, in preserved specimens, the anterior end is more 

 bluntly rounded off than the posterior. When the body- 

 length is marked out into fourths, the ventral siicker lies at 

 the beginning of the second quarter. 



The body is covered by small, backwardly directed spines, 

 densely arranged on the anterior part of the body, and gradu- 

 ally becoming fewer towards tlie posterior end. The spine? 

 are narrow and pointed, wider and thicker at the base, regu- 

 larly arranged in transverse rows, 00115 mm. long, 0-0023 

 mm. broad, 0-0092 mm. apart at the level of the gonads. They 

 are present both on the dorsal and ventral surfaces, right up 

 to the posterior end, differing in this respect from Distomnrn 

 ancinJe Tiiihe, where, on the dorsal surface, they cease aboiit 

 the middle of the body ('Liihe 60). The opening of the oral 

 sucker in the living worm is terminal or slightly subterminal : 

 the exeretorv pore is at the extreme posterior end ; the genital 



