242 ANNALS OF SCOTTISH NATURAL HISTORY 



a minute form recently described by Rousselet 1 as Notops 

 minor, n. sp. Of this species the details given are as yet 

 few. The two forms are similar in size, but the foot in 

 Mr. Rousselet's species seems to be much nearer the posterior 

 extremity : the two toes are conspicuous : and the blue 

 colour of the stomach, so constant and characteristic a feature 

 of ours, is not observed. 



Copeus Ehrenbergii, Gosse = Notommata Copeus, 



Ehrenberg. 



In Messrs. Hudson and Gosse's " Rotifera " (vol. ii. p. 28), 

 Mr. Gosse notes that this rotifer, the first and typical species 

 of his genus Copeus, has apparently not been re-observed since 

 its description by its discoverer, though several other closely 

 allied but distinct species are now known : of these the 

 nearest ally appears to be Copeus labiatus, Gosse, which indeed 

 Mr. Gosse at first referred to the true Notommata copeus of 

 Ehrenberg. I have found in the neighbourhood of Dundee 

 several specimens of a form which appears to be identical 

 with that figured by Ehrenberg, and removes accordingly any 

 doubt as to the validity of the original species. 



According to Dr. Hudson (" Rotifera," App. p. 19), Copeus 

 Ehrenbergii is (from its description) so like C. labiatus, when 

 its auricles are withdrawn, that it might easily be mistaken 

 for that animal : it differs from C. labiatns in the shape of 

 the front, in the possession of large telegraph-like auricles, in 

 the much smaller size of its ciliated lip, and in its foot having 

 three joints instead of two. 



Our species resembles C. labiatns in size and in 

 general shape. When swimming, it is about -$ inch 

 long, narrow and cylindrical anteriorly, posteriorly broad 

 and ventricose. The face is covered (as for instance in 

 Notommata aurita) with short cilia, and runs downward 

 exactly as in C. labiatns into a pointed, channeled lip, the 

 groove in which is lined by a continuation of the same cilia. 

 At certain times, when the animal is swimming freely in the 

 water, the great lateral, "telegraph-like" auricles are seen 



1 " Journ. of the Quekett Microscopical Club," (2). iv. p. 359, pi. xxiv. figs. 

 9-10, Jan. 1892. 



