147 



ON BRACHIONUS SERICUS, n. sp., A NEW VARIETY 

 OF BRACHIONUS QUADRATUS, AND REMARKS ON 

 BRACHIONUS RUBENS, OF EHRENBERG. 



By Charles F. Eousselet, F.R.M.S. 



Bead June list, 1 ( .»07. 



Plates 11 and 12, 



Brachionus sericus, n. sp. 



Ever since 1895 I have been acquainted with a species of 

 Brachionus which appeared to be new, but which I did not then 

 describe as such owing to the confusion produced in my mind by 

 the inaccuracies in the published figures of some of the old 



species. Having in the meantime seen and studied most of the 

 known species of Brachionus and their varieties, I am able to 

 add the above as a good new species to the Kotatorian fauna 

 under the name of Brachionus sericus, Fig. 1, PI. 11. 

 The specific characters may be stated as follows : 

 Lorica with six nearly equal, straight occipital teeth, with 

 shallow median sinus ; mental edge ondulate, with rounded notch 

 in the middle ; lorica rising posteriorly to form an overhanging 

 border, which may be either simply rounded, or may extend to 

 form a considerable pointed projection ; lorica covered all over 

 with line longitudinal wavy lines, giving the appearance of 

 " watered silk." 



-My first acquaintance with this new species occurred in May, 

 1895, when I found it in one of the Totteridge ponds which we 

 visited in the course of a Quekett excursion. Afterwards I 

 obtained it sparingly in various places around London, particu- 

 larly in Epping Forest, usually in small ponds full of decaying 

 leaves, with clear brownish water ; and Mr. Scourfield sent it to 

 me this spring from Snaresbrook. It has also been sent to me 



