Rotifera of the Family Asplanclinida3. 



29 



Sete Cidades. It is found in compara- 

 tively small numbers in the surface- 

 fishings, but swarms at a certain depth. 



No doubt this Rotifer feeds by pre- 

 ference at night ; tlie stomachs of the 

 numerous individuals which have passed 

 under my eyes, and which I examined 

 carefully in order to detect Protozoa in 

 them, were absolutely empty, 



I have seen no males, and it is pro- 

 bable that at the period of my investi- 

 gations (July 9) they are still very rare. 

 The winter eggs, however, had not 

 made their appearance. 



I beg Dr. O. E. Imhof, of the Uni- 

 versity of Zurich, to accept the dedica- 

 tion of this new species of Asplanchna. 

 This homage is due to him for the series 

 of interesting memoirs in which he has 

 been the first to show the considerable 

 part taken by the Rotifera in the con- 

 stitution of the lacustrine pelagic faunas. 



Masticatory apparatus of 

 Asplanchna Inthoji, X 

 700. 



The figure does not suffi- 

 ciently show the bifid 

 character of the extre- 

 mities of the jaws. 



The Asplanchnce are not rare animals, as seems to be 

 thought by various English authors, as, for example, by Hud- 

 son, with reference to A. Ehheshornei (Hudson and Gosse, 

 'Rotifera,' vol. i. p. 122). We have only to seek them 

 where they are to be found and with suitable apparatus ; 

 they are then taken in enormous quantities. This is so true 

 that, notwithstanding their extreme transparency, certain 

 observers have detected them as it were in spite of them- 

 selves. This has been the case especially with Herrick 

 when collecting the Entomostraca of Minnesota. The 

 American author, however, does not seem to have appreci- 

 ated at its full value the importance of a discovery which has 

 just furnished a new and remarkable example of the singular 

 homogeneity of the lacustrine pelagic faunas and the vast 

 geographical distribution of the types which constitute it. 

 Nevertheless Herrick has figured one of the Asplanchnce 

 which he collected so clearly to enable us to recognize in it an 

 undescribed species and to describe it, at least briefly. 



