232 Transactio7is of the Society. 



Zoo at Palermo, Buenos Ayres, and one sample of moss from trees 

 at Tigre, a few miles out of Buenos Ayres. 



In Brazil all the collecting was done in and around the city of 

 Kio de Janeiro. In the squares and parks of the city there are 

 many ponds, and the mountain tops have a luxuriant growth of 

 moss. Near the Botanic Gardens there is a large lagoon of brackish 

 water, separated from the sea only by a sand bar. 



Some of the ponds of Eio proved exceedingly productive. The 

 greatest number of species occurred in the water-lily pond in the 

 Pra9a Kepublica. A small pond in the Botanic Gardens was very 

 prolific in species of the family Cathypnidpe, The salt lagoon 

 between the Botanic Gardens and the sea was most interesting of 

 all. There appeared to be no free communication with the sea, yet 

 there were some indications that it felt the influence of the tide. 

 Barnacles encrusted the stones on the shore, and were exposed 

 above the level of the water. The water was very salt to the taste. 



The fauna of the lagoon included many undoubted fresh- water 

 species, some which are characteristic of brackish water, and a 

 number of previously unknown species. A list of these curiously 

 associated species should be useful. 



Fauna of the Salt Lagoon at Rio. 



Polyarthra platyptera Ehr. JBrachionus angularis Gosse, and 



Triarthra terminalis Plate. var. caudatus Daday in many 



Battulus stylatus Gosse. forms. 



Cathypna aculeata Jakub. B. hakeri Miiller. 



C. grandis sp. n. B. falcatus Zach. 



C. hastata sp. n. B. mulleri Ehr. 



Monostyla hulla Gosse. B. pala Ehr. 



M. lunaris Ehr. B. trahea sp. n. 



M. obtusa sp. n. Anuria aculeata Ehr. var. 



M. punctata sp. n. Anurieopsis liypelasma Gosse. 



Metopidia triptera Ehr. Pedalion oxyure Sernow. 



M. quinquecostata Lucks. 



Historical Sketch. — The works dealing with the Eotifers of 

 South America number only about a dozen. 



Ehrenberg, in his Mikrogeologie, 1854 (9) has a few doubtful 

 records of Rotifers, chiefly Bdelloids, identified from contracted 

 specimens. 



Schmarda, in his Neue wirbellose Thiere, 1859-1861 (28) 

 records a great many species, many of which have been considered 

 by later authorities as unrecognizable. Without pretending to 

 judge of the validity of his species, I give his records for what they 

 are worth. 



Certes, 1889 (^), notes Rotifer vulgaris in Patagonia. 



