TREMATODES OF AUSTRALIAN BIRDS. 



235 



Spines absent, ventral sucker present. Ovary compara- 

 tively long, tubular and bent into a series of five or six 

 ivaves or loops. Yolk glands occupying the posterior third 

 of the body. 



Type species A. terrigalensis, sp. n. 



Host. — Larus novce-hollandice. 



Type specimens in the Australian Museum, Sydney, No. 

 W. 443. 



In a gull, Larus novce-hollandice, shot at Terrigal, New 

 South Wales, I found in the intestine a number of small 

 worms each surrounded by a droplet of blood. These 

 proved to be Bilharzia-like forms which probably escaped 

 through a wound from the intestinal blood vessels into the 

 intestine. In most cases the female was found to be 

 occupying the gynecophoral canal of the male. Though 

 fairly closely related to Ornithobilharzia they proved to 

 belong to none of the already established genera of this 

 family, so that I propose for their reception a new genus 

 Austrobilharzia. 



In Austrobilharzia terrigalensis the males average 4 

 mm. in length, while the females are 5 mm. or a little 

 longer. The shortest male measured 3*5 mm., and the 

 female with it 4*5 mm. in length. In many cases it was 

 not possible to measure the length of the female exactly, 

 owing to its anterior thread-like part being bent into a 

 number of waves. Spines were quite absent from the 

 integument of both sexes except on the inner surface of 

 the ventral sucker of the male where very small fine spines 

 occurred. Both the oral and the ventral suckers of the 

 male are well marked off from the surface of the body, the 

 latter especially so, for it is distinctly stalked (fig. 20). The 

 suckers are approximately equal and show very little 

 variation in size, the diameter being 0*175 mm. In all the 

 males the body exhibits a marked antero-posterior curva- 



