List of New Rotifers since 1889. By.C. F. Rousselet. 149 



to be deprecated. Usually the figure is the most important part of 

 the account of a rotifer, and a description could, as a rule, be much 

 better dispensed with than a good figure. To sum up, therefore, any- 

 one who proposes to publish a description of a rotifer as new should 

 fulfil the following conditions : — 



1. Not only Hudson and Gosse's Monograph, but all subsequent 

 papers containing descriptions of rotifers in any way related to the 

 one in hand, should be consulted. 



2. New species should not be described as a result of the dis- 

 covery of some hitherto unmentioned anatomical detail in an otherwise 

 known species. 



3. Great care should be exercised not to describe as new species 

 mere variations of an old species. 



4. If any doubt can possibly exist, the figures and descriptions 

 should be submitted, before publishing, to some expert who has all 

 the literature at hand. 



5. A description of a new species should be accompanied by a 

 detailed comparison with any very closely related species that may 

 exist, to show wherein this one differs, and why it is considered new. 



6. Every description of a new species should be accompanied by 

 a good figure or figures." 



An excellent model of how the work of recording the fauna of a 

 lake or a district should be done is furnished by Dr. E. F. Weber's 

 ' Faune Eotatorienne du Bassin du Leman,' in which about 125 

 species, accurately described and beautifully figured, are recorded, but 

 only one new species is named. 



The time, surely, is past when new species of rotifers can be 

 found wholesale in any lake, and with the publication of these lists, 

 together with the titles of papers, the work of identification, always 

 laborious, is rendered comparatively easy. I may add that I shall 

 always be glad to assist in identifying sketches and descriptions of 

 rotifers, or still better preserved specimens, that may be sent to me 

 addressed to the Eooms of this Society at 20 Hanover Square, 

 London, W., a task which is facilitated by my collection of slides of 

 preserved Eotifera containing at present over 300 different species. 



As before, the numbers behind each name in the subjoined list 

 refer to the Bibliography at the end. 



Rhizota. 



Melicerta fiocculosa Kellicot (109) ( = ?M.janus Hudson). 



fimbriata Shephard and Strickland (122) ( = ?M. i tubi- 

 eolaria Ehrbg.). 

 Lacinularia elliptiea Shephard (120). 

 ,, striolata Shephard (121). 



Megalotrocha binotata Daday (102) { = M. semi-bullata Thorpe). 



