[ 664 ] 



XXXIX. 



ox THE ROTIFERA OF THE COUNTY MAYO. By J0H:N' 

 HOOD, F.E.il.S., Dundee. (Plates XXI. akd XXII.) 



■j^COlOnrN'ICATED BY PEOFESSOE, d'aECY W. THOITPSOJT TO THE COimiTTEE 

 APPOINTED BY THE ACADEMY TO EEPOET TTPOJT THE FLOBA AI\T) FAXTNA 

 OF EEELAXD.] 



[Eead April 8, 1895.] 



DrrRTNG f our short visits to the west of Ireland (in August, 1889, 

 June, 1891, August, 1892, and July, 1894), I chiefly occupied myself 

 in the study of the rich fresh -water fauna of that region. The follow- 

 ing list includes tlie species of Eotifera ohserved by me in the lakes, 

 ponds, marshes, and bog-pools within a radius of some sixteen miles of 

 the town of "Westport, together with a few marine species collected on 

 the neighbouring shore. My stay in the country on these several 

 occasions has been far too short to give this list any claim to complete- 

 ness. It is published merely as an instalment of, or contribution 

 towards, a more extensive catalogue, but nevertheless it may give some 

 idea of the exceeding richness of that abundant fauna. A longer 

 residence in the district could hardly fail to result in the discovery of 

 many other local species ; the want of boats on the many small lakes 

 has doubtless prevented the discovery of many forms which haunt 

 the deeper waters ; and the circumstance that my visits have all taken 

 place nearly at the same time of year may have led to the omission of 

 many more which become plentiful at other seasons. As a case in 

 point, to show how definite in the time of their appearance are certain 

 species of Eotifera, I may mention that, in a certain little lake near 

 Westport, I found the beautiful Lacinularia socialis make its appear- 

 ance at the end of July in the several years 1889, 1892, 1894, as 

 precisely to its season as the lapwing or the swallow. In 1891, my 

 visit to the west was a month earlier, and not an example was to be 

 found, though I searched for the species in every lake in the district. 

 Dr. Plate mentions the annual appearance of L. socialis about the 

 middle of June, in the neighbourhood of Jena. Very few countries 

 ofier such advantages to the student of freshwater life as the west of 



