215 



Specific 

 Characters 



On Diglena rostrata: a New Rotifer. 

 By F. R. Dixon-Nuttall, F.R.M.S., and Rev. R. Freeman, M.A. 



(^Read December 20f//, 1901.) 



Plate 9. 



''Body : long, thin ; dorsum, slightly arched ; venter,, 

 flat. 



Face : long, prone, with a long projecting hook. 



Eyes : tw^o, red, frontal. 



Foot : thin, cylindrical. 

 ^Toes : long, blade-shaped. 



Towards the end of April, 1901, we found this graceful Diglena 

 in water taken from the large lake in Knowsley Park, Lancashire, 

 which at once struck us as being a new species, both on account 

 of its hyaline appearance, and also on account of the long pro- 

 jecting prow-like beak. From this latter feature we decided to 

 name it rostrata, after " rostrum," the beak or prow of a boat. 



The skin is soft and very transparent, but apart from the two 

 folds in the neck, and the parts posterior to the lumbar fold, the 

 animal is not given to contortion, so that its general outline 

 remains constant. 



Viewed laterally, the dorsum is slightly arched towards the 

 lumbar regions, but hardly sufficiently so to destroy the graceful 

 outline. It rounds rapidly to a lumbar fold, and thence tapers 

 to the cloaca. 



Viewed dorsally, the body is almost cylindrical, but slightly 

 fusiform, tapering to the width of the foot at the lumbar fold. 



The foot is cylindrical, with a shght tail-like projection, carrying 

 no seta, as in D. UQiciiiata. The toes are long, cylindrical, slightly 

 decurved and outcurved, and carried wide apart when viewed 

 dorsally. 



The head is produced into a long hooked beak, which, with two 

 red eyes situated just beneath its base, is the most striking 

 feature of this rotifer, and can be easily observed under low- 

 power objectives. The face is prone, elongated, and well covered 



