BY S. J. JOHNSTOX. 335 



Host, Hyla ewingii, in the duodenum. 



Type-specimen in the Australian Museum, No. W.343. 



Thirty-two specimens of Hyla ewiiigil, a frog fairly common 

 in the neighbourhood of Sydney, yielded a single specimen of 

 this fluke, which occurred in the duodenum. It is a thin, deli- 

 cate worm, with the posterior end distended with eggs; and, 

 in the process of mounting, it became broken in two, just 

 where the coils of the uterus, crowded with eggs, begin to fill 

 up the body. At first, I intended not to describe it till more 

 material became available, but the interesting variation it 

 shows in the position of the ovary, combined with the other 

 well-marked specific characters, decided me to publish a descrip- 

 tion of it with the others now, in order to make the group more 

 complete. 



Mesoccelium oligoon, sp.n. 



(Figure 14.) 



Diagnosis. — Small, delicate worms, oval, 1-53 mm. long, by 

 0-59 mm. broad ; body covered with very small spines, com- 

 paratively few in number: oral sucker subterminal, 0-215 mm. 

 in diameter, ventral sucker at the junction of the anterior and 

 middle body-thirds, small, 0129 mm. in diameter; ratio of 

 oral to ventral sucker, 5:3; pharynx globular (0-065 mm.); 

 intestinal limbs short, of unequal length. Testes polyhedral, 

 large, 0-165 x 0-099 mm, about one-ninth of the body-length; 

 ovary oval, with smooth contour, large (0-133 x 0-09 mm.), situated 

 behind the right testis. Yolk-follicles rounded to oval, 0-028- 

 0-052 mm. long, comparatively numerous, about 70 on each 

 side, closely arranged in a somewhat triangular group on each 

 side of the oesophagus, ertendivg barhirards laterally to beyond 

 the intestinal limbs. Eggs few in number, comparatively large, 

 0039-0-052 mm. long, by 0028 mm. broad, average length 



* oXt-yos, few; tioi', egg. 



