Mr. H. A. Bay lis on Dicroccelium lanceatum. 113 



0*37 mm.*. Tlie ventral sucker is situated 0*7 mm. behind 

 it, and measures 0"4 mm. across. The mouth is followed 

 immediately by a small, almost globular pharynx, measuring 

 0"15 mm. in length, and this is succeeded by an oesophagus 

 0*2 mm. long. The two simple intestinal diverticula extend 

 backwards to within a little more than 1 mm. from tiie 

 ])osterior end. They lie, for the greater part of their length, 

 near the lateral margins of the body. 



The excretory vesicle is small and inconspicuous. Its 

 pore is terminal. 



The genital pore is median, situated between the two 

 suckers and at about the level of the bifurcation of the intes- 

 tine. The testes are large compact bodies, slightly lobulated, 

 especiall}^ on their lateral margins. They lie, as has been 

 noted already, symmetrically opposite to each other, imme- 

 diately behind and at the sides of the ventral sucker, and 

 between the intestinal diverticula. Each testis measures 

 about 0"8 mm. in lengtli and 0"6 mm. in width. The ovary 

 is a body of variable shape, but usually somewhat lobate; 

 it is situated close behind the testes, but its position shows 

 considerable variation. It appears to be rather more com- 

 monly situated on the right side than on the left, but in 

 three out of eight stained examples the ovary was placed 

 behind the left testis. There is a rather large rounded 

 receptaculum seminis, situated just dorsally to the posterior 

 edge of the ovary. Laurer's canal is present, and a shell- 

 gland, not differing from tliat of the typical D. lanceatum. 

 The cirrus-sac is about 0*4 mm. long and 0*15 mm. wide. It 

 contains a coiled vesicula seminalis. The cirrus-sac partici- 

 pates in the variability of position shown by the ovary and 

 its associated organs. Thus, when the ovary is on the right, 

 the cirrus-sac lies to the right of the terminal portion of the 

 uterus; when the ovary is on i\\Q left, the positions of the 

 genital ducts are generally reversed. 



The vitelline glands lie within the middle third of the 

 body, and extend along the sides as a series of lobes of 

 various sizes. The two vitelline ducts are given off somewhat 

 in front of the middle of the glands, and cross the body to 

 unite into a much wider single duct just behind the ovary, 



Ttie uterus tills almost the whole of the middle and 

 posterior portions of the body, from the level of the anterior 

 end of the vitelline glands to the tail. Its coils, for the most 



• This and the following measurements are taken from an example 

 mm. long, and are therefore to be regarded as somewhat below the 

 mean. 



Ann. & Mwj. N. Hist. Ser, 0. Vol. ii. 8 



