282 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



fully expanded. The skin is almost everywhere smooth, 

 and only in one place shows the characteristic plications. 

 The ventral sucker is rather more than twice the diameter 

 of the oral one, and is situated well forward. There is a 

 short pharynx followed by a very short oesophagus. The 

 forks of the intestine are straight and cylindrical, and 

 extend well down into the appendix. The ovary is 

 situated about halfway between the extremities and is 

 oval in shape. Immediately behind it are the vitellaria, 

 which are two in number, small and nearly globular in 

 shape, and in close contact with the ovary. The testes 

 lie midway between ovary and ventral sucker. They are 

 almost globular in shape and lie obliquely across the 

 body. Almost in contact with the anterior margin of the 

 testis are the seminal vesicle and cirrus pouch. The 

 cirrus itself is long, and is surrounded for the greater 

 part of its length with a. compact prostate gland. It 

 opens on the posterior margin of the oral sucker. 

 Apparently the female genital aperture is very near to the 

 male opening, but it was not visible in the preparation. 

 The uterus is long and greatly convoluted in the region 

 of the ovary and vitellaria. Like the intestine, it extends 

 well down into the appendix. The worm when alive was 

 translucent, but possessed no distinct colour. 



Distomum vitellosum, Linton.* 



From Flounders (Pleuronectes flesus), Piel tanks. 



In June, 1906, Mr. A. Scott dissected several mature 

 flounders which had been kept in the tanks at Piel 

 Hatchery during the whole of the previous winter, and 

 found a great number of mature distomids in the 



* Linton : Bull. U. S. Fish. Comm., Vol. 10., 1899, p. 290, pi. 37, 

 fig. 38. 



