BY S. J. JOHNSTON. 109 



extending as far forwards as the position of the ventral sucker. 

 It is roughl}' cubical in shape and is partly overhung by a lip or 

 narrow hood formed by the flexed lateral flaps, which are fused 

 together for a short distance at their posterior ends. It is split 

 in the middle (PL v., fig. 2). 



Oral sucker well formed, orbicular, larger than the pharynx, 

 about equal in size to the ventral sucker. Oral sucker 0-06 mm. 

 in diameter, pharynx 0'05 mm., ventral sucker 0062 mm. 



On either side of the oral sucker is the conspicuous opening of 

 a group of unicellular glands. The ventral sucker is surrounded 

 by a group of unicellular glands, each cell opening on the surface 

 by a separate duct (PI. v., fig. 4). 



The alimentary canal divides into two immediately on leaving 

 the pharynx, and the two well-developed arms are continued to 

 the posterior end of the body. 



The ovary is large, rounded and situated far forwards in the 

 posterior body-region, near its junction with the anterior body- 

 region. The testes are large, situated one behind the other, and 

 behind the ovary. The uterus occupies a considerable part of the 

 space in the posterior body-region; eggs large. 



The vitelline glands are very numerous, extending from one 

 end of the body to the other and into the clinging plug. 



Found in the duodenum and small intestine of the Lausfhins" 

 Jackass, Dacelo gig as, Bodd. Collected at Jervis Bay, N.S.W. 



Hemistomum intermedium, sp.n. 

 (Plate v., figs. 7-10.) 



Length 3-6 mm. ; length of anterior body-region 0*67 mm.^ 

 length of posterior region 2 93 mm. 



The anterior body-region is well marked off from the posterior 

 and is strongly bent back on the posterior in a dorsal direction, 

 giving the body a U-shaped form (PI. v., figs. 6 and 7). 



The foldings of the lateral body-edges ventralwards very 

 marked; these folds are fused for some distance in their posterior 

 part, so that the cup-shaped anterior body-part of the genus 

 Holostomum is approached. In its clinging apparatus, too, this 



