216 



S. J. JOHNSTON. 



The vesicula seminalis lying within it is not coiled. The 

 uterus has a descending limb running backwards between 

 the testes to a point near the posterior ends of the intes- 

 tinal limbs. From this point it bends sharply round and 

 runs forward in a number of close coils, again passing 

 between the testes on its way towards the genital opening. 

 Its terminal part which is thick- walled and muscular, may 

 be distinguished as the vagina. The uterine coils fill up 

 the field between the intestinal limbs behind the testes. 

 A receptaculum seminis and Laurer's canal are absent. The 

 yolk glands consist of very numerous, small, rounded fol- 

 licles 0*011 to 0*014 mm. in diameter. In front they are 

 confined to the space between the intestinal limbs and the 

 lateral edges of the body, but behind the testes the field of 

 these glands widens out, crossing over the intestinal limbs 

 and invading the space between them to a certain extent. 



The average size of the eggs is 0*031 x 0'017 mm., the 

 largest being 0*033 mm., and the smallest 0*029 mm. long, 

 while the breadth remains practically constant. 



In its structure this species appears to resemble more 

 closely than other species, P. maculosus, Rud., parasitic in 

 various species of swallows (Hirundo) in Europe. 



Plagiorchis clelandi, sp. n. (Fig. 11a.) 



Diagnosis. — Small worms, with sides parallel for the 

 most part and the body narrowed towards each end. 

 Integument in the anterior end covered with small scale- 

 like spines. Suckers almost equal in size. Intestinal limbs 

 wide and voluminous. Yolk-glands closely surrounding the 

 intestinal limbs and not extending inwards; anteriorly 

 they only reach a point half-way between the pharynx and 

 the ventral sucker. 



Host. — The Fairy Martin, Petrochelidon ariel. 



Type specimen in the Australian Museum, Sydney, No. 

 W. 435. 



