0. F. EOUSSELET OX THE ROTATORIAN FAUNA OF BOSTON. 339 



species, I prefer not to give it a name. Perhaps some member 

 of the Boston Society of Natural History may look for it and 

 supply a good description and figure. 



It might he suggested that this Oecistes may have been fixed 

 and knocked off its support ; but as I did not take up any weed, 

 and found quite a score of specimens in the material collected 

 with the plankton net, and, moreover, saw animals freely 

 swimming in a micro-trough under the microscope, I do not 

 think I am in error in considering this a free-swimming form. 

 We have several free-swimming Floscules, and therefore there 

 seems no reason why an Oecistes should not take to a free and 

 roving life. 



The following other species of Rotifera found in this collection 

 may be specially mentioned : 



Pterodina parva, characterised by the peculiar pear-shaped 

 lorica, w^as found only once before by Dr. Ternetz, near Bale, in 

 Switzerland ; his figure enabled me to recognise it without 

 difficulty. In my paper on " Some Little-known Species of 

 Pterodina," I have reproduced Dr. Ternetz's figure, but most 

 unfortunately a serious error has crept into this copy. The foot 

 is there indicated as if issuing from near the middle of the lorica, 

 whilst the position of the opening is near the posterior margin 

 on the ventral side. Dr. Ternetz's drawing is perfectly correct, 

 and, as a figure is always remembered better than a description, 

 I have reproduced a correct figure of this rare Pterodina on 

 Plate 27, Fig. G. 



The size of Pterodina parva is 99/x (tt\q in.) long by 95 /x 

 (o^ T in.) wide. 



Taphrocampa viscosa is a rare species, found before only in 

 Finland by Dr. Levander. 



Pohjcliaetns subquadratus, Ploesoma lenticulare, Polyarthra 

 aptera are all three rare and not often seen. 



Synchaeta. — Five species of the genus were readily recognised : 

 S f . pectinata and oblonga are common everywhere, but longipes, 

 stylata, and cecilia are rather rare. 



In the afternoon of August 22nd the members of the Zoo- 

 logical Congress were hospitably received at Wellesley College, 

 a Ladies' University near Boston, in the extensive and beautiful 



* Journ. Quehett Micr. Cluh, vol. vii. (1*98) pp. 24-30. 



