202 Transactions of the 



cules," yet bearing no wheels at all. On communicating this fact 

 to Lord Osborne, with my opinion that the rotifer was new to 

 science, he looked through his large stock of tanks, and found 

 scores — hundreds of them. He could not, however, be induced to 

 undertake the task of introducing the stranger to the scientific 

 public. 



Little less reluctant at that time, I merely exhibited the new 

 rotifer under the name of Callidina vaga, at a soiree of the Old 

 Change Microscopical Society, in February, 1869, and again let it 

 retire into private life. 



Some time after this, Dr. Hudson met a rotifer whose head was 

 shaped like the " top joint of a thumb," * and he speaks regretfully 

 of their short acquaintance in the first excellent paper on his 

 Pedalion mira. Seeing that he had happily given the most striking 

 peculiarity of G. vaga, I at once sent a few dry specimens, which 

 he moistened and immediately identified ; thus reviving with plea- 

 sure an old friendship, and giving me the great advantage of 

 forming a new one with the best active observer and describer of 

 rotifers we now possess. 



It is, perhaps, barely necessary to state that all due care has 

 been taken to prevent the introduction of a previously-described 

 rotifer under another name. I can find nothing like G. vaga 

 described anywhere ; the G. constricta of Dujardin bears, indeed, in 

 the head a very remote resemblance to it, but description there is 

 next to none ; while the C. bidens of Mr. Gosse is very plainly a 

 different species, as shown by that gentleman's notes and figures in 

 an invaluable MS. volume, most courteously lent to me by the 

 author. 



For ranging with the most generally accepted classification of 

 Kotifera, the specific character of this new member of the family 

 Philodinaea, genus Callidina, may be thus condensed : — 



G. vaga (mihi). — Figure depressed-fusiform ; crystalline, and 

 nearly colourless ; flat, frontal lobes continuous with ventral sur- 

 face, and uniformly covered with short cilia, not disposed as peri- 

 pheral wreaths ; non-retractile proboscis, with broad anterior hook ; 

 two coarse and numerous fine teeth in each jaw. Progression by 

 crawling. Length 1-50" to 1-36". 



As regards habitat little information can be given : the rotifers 

 are found in certain open stone vases in the grounds of Lord 

 Osborne's house near Blandford ; and these at times get partly filled 

 by the rain, while the wind drifts in dead leaves, and other matter, 

 which by their decomposition seem to yield suitable food. So far 

 as my experience teaches, similar circumstances in and near London 

 do not produce the same results. Philodinae of different species 

 have been gathered sparingly and in sooty condition from a house- 

 * 'Monthly Micro. Journal,' Sept. 1871. 



