rgii- Southern. — Some New hish Worms. 7 



Professor Benham recorded^ the discovery of a fresh- 

 water Nemertine Hving in the River Cherwell, at Oxford. 

 He found only a single immature specimen which was 

 accidently destroyed before the specific title was definitely 

 determined. He gives some details of its structure, which 

 agree closely with observations on the Irish specimens. 



Miss Sheldon sa\s^ that Beddard found a Nemertine in 

 one of the tanks in the Botanic Gardens in Regent's Park, 

 London, which he referred to the species Tetrastemma 

 (Prostoma) aqiiarum dulcium, Silliman. The opinion is also 

 given that " it had almost certainly been introduced among 

 the roots of plants, and cannot be considered as a British 

 species." As the last-named species is now considered as 

 probably synonymous with Prostoma clepsinoides, Ant. 

 Duges, this expression of opinion is rather too emphatic. 

 These are the only records of fresh -water Nemertines in the 

 British Isles, and it is highly probable that they refer to 

 the same species, for which the name Prostoma clepsinoides, 

 Ant. Duges, has priority. 



Seven species of fresh -water Nemertines, all belonging 

 to the genus Prostoma (Tetrastemma), are recognised by 

 Burger {torn, cit., p. 68). Our knowledge of their anatomy 

 is very slight, and is in great need of revision and enlarge- 

 ment. Burger rehes chiefly on their methods of reproduction 

 to distinguish the species, a most unsatisfactory m.ethod in 

 practice. As our knowledge of the group increases, it will 

 probably be found necessary to reduce the number of 

 species. 



The Irish specimens were 10-15 mm. long. The majority 

 were immature, but a few of them bore eggs. They were 

 reddish -brown, brick-, or rose-coloured ; young specimens 

 were pale buff in colour. There are three pairs of eyes on 

 the head, the distance between the first and second pairs 

 being slightly greater than that between the second and 

 third. 



The epidermis bears a large number of clear oval glands. 

 There is only a little faint yellow pigment in the skin, but 



1 Nature, vol. xlvi., p. 6ii. 1892. 

 'Cambridge Natural History, vol. ii., p. 118. 



