422 O. WESTERN ON SOME FOREIGN ROTIFERS. 



7. Brachionus-hrevispinus, Ehr., vide Hudson and Gosse's 

 Supplement. 



8. BracMonns rhenanus, Lauterborn. — Both these Rotifers are 

 to be found at the Botanical Gardens, and Mr. Rousselet and I 

 had arrived at the conclusion that Lauterborn's hint that they are 

 varieties of B. Bakeri really expresses the truth. Biifinger in his 

 paper before referred to confirms this idea. 



9. Bosphora elongata, Ehr., Hudson and Gosse's Supplement. — 

 This is common enough, and agrees very vfell with the figure 

 given. Shortwood Common, near Staines, is almost a sure place 

 to find it. 



10. Eospliora naias, Ehrenberg, Hudson and Gosse's Sup- 

 plement. — There is some doubt as to whether this is distinct from 

 Notommata naias. I often find Rotifers which are hardly dis- 

 tinguishable except for the eye-spots, in one case three, and in the 

 other one only. So far as I can judge the anterior two in the 

 Eosphora form are as perfect eye-spots as any we see in Rotifers, 

 and I believe the two Rotifers to be distinct. Eye spots are, how- 

 ever, very unreliable features by which to determine either species 

 or genera, on account of their evanescent character, in the Rotifera 

 being often visible only in the very young animals, and disappear- 

 ing altogether in adults. More than this, I have frequently found 

 specimens of this very Notommata naias in which I could see no 

 signs of eye-spot, and a very curious instance has just been brought 

 to my notice by a friend who had a gathering of these Rotifers, 

 which, when first he examined them, had it as usual, but in 

 which it entirely disappeared after he had kept them a few weeks 

 in comparative darkness. 



11, Notommata tuba, Ehr. — This was very doubtfully included 

 as a British species by Mr. Gosse on the authority of a rough 

 sketch from Dr. Collins' note-book. It is undoubtedly entitled to 

 a place in our catalogue. I have frequently found it. It was 

 identified by Dr. Hudson himself just after the completion of his 

 book, and I have since been able to send it to many friends, for it 

 has frequently turned up in my aquarium, and I think always after 

 expeditions to Staines, at which place I first found it. Tlie original 

 figure by Ehrenberg is the best published, but this Rotifer must 

 be seen alive for its full beauty to be appreciated. It is, as 

 suggested by Mr. Gosse, most closely allied to Hydatina. 



12. Seison gruhci, Claus., Hudson and Gosse's Supplement. — 



