330 ON SOME TREMATODE PARASITES OF AUSTRALIAN FROGS, 



at the anterior end marked off into two very shallow pockets. 

 Testes entire, syiwnitti tcally placed on titker side of the middle 

 line, near and mostly behind the ventral sucker : ovary entire, 

 uj a variable position behind the testes; vesicula seminalis, 

 cirrus-sac, prostate, and penis moderately or well-developed ; 

 genital opening in the middle line, between the suckers : recep- 

 taculum seminis and Laurer's canal present. Volk-glands a 

 single group of rounded follicles on either side, in the anterior 

 part of the body, not ^wss/»r/ invards beyond the intestinal 

 limbs. Coils of the uterus in transverse loops, filling up most 

 of the body-space behind the gonads, only in the terminal 

 part passing in front of these. 



In the intestine of frogs (Anura). 



Mesoccelium mesembrinum,* sp.n. 

 (Figures 13, 69-76.) 



Diagnosis. — Moderately small worms, length 2-3 mm. Oral 

 sucker the larger, ratio of its diameter to that of the ventral, 

 3:2. Body closely covered with small, backwardly directed 

 spines, gradually becoming fewer and smaller up to the pos- 

 terior end. Pharynx well developed ; intestinal liiiibs reach- 

 ing the middle of the body. Excretory vesicle tubular, reach- 

 ing up to the shell-gland, inconspicuously divided in its an- 

 terior part. Testes symmetrically placed near the ventral 

 sucker ; ovary behind the right testis ; copulatory organs 

 moderately well developed. Genital opening in the middle 

 line, halfway between pharynx and ventral sucker. Recep- 

 taculum seminis and Laurer's canal present. Uterus filling 

 up the posterior part of the body. Yolk-glauds laterally 

 placed in the anterior part of the body, not passing innards 

 beyond the intestinal limbs, nor backwards beyond the ovary. 

 Eggs thick-shelled, light brown at first, becoming dark brown, 

 0-040 mm. long, and 0-025 mm. broad. 



Host, Uyla cwrulea, in the duodenum. 



* jhorijjhfipivo'i, southern; referring to its geographical distribution. 



