198 S. J. JOHNSTON. 



are broad, elliptical and pointed at the ends, and vary a good* 

 deal in size, the smallest measuring 0'091 x 0*069 mm.,, 

 and the largest 0*096 x 0*074 mm. 



This species is obviously closely related to H. rhigedana 

 Dietz, (13) parasitic in the intestine of Numenius arabicus 

 and N. arquatus, of the Sinai peninsula. Among the differ- 

 ences one finds in these two forms is the number of spines 

 on the border of the head-collar, twenty-four in the one 

 and thirty in the other. While the ratio of the diameter 

 of the oral to the ventral sucker is 1 : 4 in the Australian 

 species, it is 1 : 3 in the Asian. The size of the spines on 

 the posterior part of the body seems to be considerably 

 larger in the Australian form, and the gonads much closer 

 together. 



ACANTHOPARYPHIUM SPINULOSUM, Sp. n. (Fig. 7.) 



Diagnosis. — Small form, 5*55 mm. long by 0*8 mm. broad- 

 Integument of the anterior part of the body spiny. Head- 

 collar only half as broad as the body. Collar spines twenty- 

 three in number. Ratio of oral to ventral sucker 2 : 7. 

 Ventral sucker situated entirety in the first quarter of the 

 body length. Cirrus sac elongated, reaching back far 

 beyond the posterior end of the ventral sucker. Cirrus 

 spiny. 



Host, — Charadrius dominions, in the duodenum. 



Type specimen in the Australian Museum, Sydney, No- 

 W. 428. 



Two individuals and a number of fragments of this species 

 were obtained from the duodenum of a Golden Plover, 

 Charadrius dominions, at Cronulla, near Sydney, by Dr- 

 Harvey Johnston and Dr. J. B. Cleland. It is a small worm 

 5*55 mm. long by 0*8 mm. broad in the region of the ventral 

 sucker. There is little diminution in the width as far back 

 as the posterior testis, but from this point to the posterior 



