310 ON SOMK J'HKMATUDK PAKASITKS OF AUSTRALIAN FROGS, 



not rtdcJtiiKj in front of the int&sti/ui/ fork: behind the ov;iry 

 gradually spreading under the whole surface (jf the body. 

 Uterine loops mainly in front of the ovary. Eggs, light in 

 colour, O'U^^T X U-022 mm. 



Hosts : l/nninxii/nastiiK pp.ronii and Hijitt aurt^a, in tlie duo- 

 denum,. 



Type-specimen in the Australian Museum, No. W.334. 



These worms are fairly common in the duodenum of Limno- 

 dynastta peronii, and much less common in H j/la aurea. At 

 first, no record was kept of the frequency of occurrence, but 

 in the last 47 of I., jferonii examined, this fluke occurred nine 

 times with a yield of 117 specimens. Altogether, I have col- 

 lected 214 specimens of this species from 150-200 Limnodynas- 

 tes; and 35 from Plyla aurea, in which I have found it only 

 four times out of several hundred specimens examined. The 

 greatest number found in one frog was 25, the lowest 4. They 

 are very active and extensible, and are capable of stretching 

 out to twice the length of the animal when in a state of rest. 

 Thirty-five were cut into sections, and most of the rest mount- 

 ed as whole-mounts. I cut so lai'ge a number, in order to 

 have plenty of material for study in regard to the egg-forma- 

 tion and the early development, to supplement the observa- 

 tions made on the living worms. 



These worms are of elongated, delicate form, oval in cross- 

 section, but a little flattened dorso-ventrally, somewhat narrowed 

 anteriorly and posteriorlv, and rounded oflF at the ends; 2-98 mm. 

 long, by 091 mm. broad. Integument densely covered by small 

 backwardly directed spines, which have become much less dense 

 at the middle of the body, and completely disaj)poar before the 

 end of the body is readied. Oral sucker subterminal, 0"243mm. in 

 diameter: ventral .sucker plac^ed at the beginuiTig of tlie second 

 quarter of the body-length, spherical, 0169 mm. in diameter : 

 ratio of oral to ventral sucker, 7 :5. Opening of oral sucker 

 on ventral surface ; excretory pore terminal ; genital pore in 

 the middle line on the ventral surface, just behind the intes- 

 tinal fork. 



