326 



CONTRIBUTIONS TO A KNOWLEDGE OF AUS- 

 TRALIAN ENTOZOA. 



No. ii. — On a new species of Distomum from the Sawfish 

 Shark, Pristiojyhorus cirratus, Lath. 



By S. J. Johnston, B.A., B.Sc, Economic Zoologist, 

 Technological Museum, Sydney. 



(Plate xiii.) 



I am indebted to Professor Haswell for three specimens of 

 this Trematode, which were found in the body cavity of the 

 Sawfish Shark, PristiojyJiorus cirratus, Lath., at Sydney. I have 

 examined several specimens of the same host since receiving those 

 from Professor Haswell, but have found no Distomes, though in 

 the body cavity of one specimen a number of eggs were found 

 which very probably belong to the same species, for the eggs with 

 their very thick shells are characteristic of the species : the 

 worms may have escaped through the abdominal pores when the 

 fish was caught. This Avorm has a very extensible neck; fasten- 

 ing itself by the ventral sucker it stretches its neck out for more 

 than an inch, longer than the body itself. 



DiSTOMUM PRISTIOPHORI, sp.n. 



Body elongated, pointed at the anterior end, and rounded at 

 the posterior, flattened dorsoventrally, with rounded sides; head- 

 lobe triangular. Average length 25 mm., breadth 6 mm. 



Oral sucker deep, cup-shaped and small ; subterminal, the 

 opening being on the ventral aspect; diameter 1*5 mm. Ventral 

 sucker orbicular, sessile, with deep cavity, larger than oral 



