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Note on the Genus Lacinularia.-'' 

 By Charles F. Rousselet, F.E.M.S. 



As is well known, up to the appearance of Hudson and Gosse's 

 monograph of the Rotifera in 1886, only one species of Lacinularia 

 was known to science — namely, L. socialis — which occurs in 

 clusters fixed to submerged plants, and is fairly common every- 

 where in Europe. 



In that same year, however, Mr. Whitelegge, of Sydney, 

 N.S.W., discovered a new and remarkable Lachiularia, which, 

 instead of being fixed to water-plants, as L. socialis, forms a 

 spherical cluster i in. to J in. in diameter attached to a peduncle 

 ^ in. long, the peduncle being formed by the fused secretion of 

 the feet of the animals. Mr. Whitelegge sent over some con- 

 tracted specimens preserved in spirit, and an account of the 

 species was published b}' Dr. Hudson, who named it L. j^^dunculata, 

 in the "Supplement" in 1889. Of course the characters of the 

 genus had to be altered in order to include this semi-free-swimming 

 form. Lately this species has again been found in abundance in 

 Victoria, Australia, by Mr. John Shephard ; and he has now sent 

 me some very fine and well-preserved colonies, prepared, according 

 to the directions I was able to send him. One of these is dis- 

 played under a microscope in the room. It will be noticed that 

 the gelatinous tubes are quite absent in this species. 



A year later another new species of Lacinularia was discovered 

 by Mr. Western at Littleton. As this formed free-swimming 

 spherical colonies like Conochilus volvox, it was named Z. nutans. 

 The characters of the genus had again to be altered in order to 

 admit this new species, which was first exhibited in this room in 

 the spring of 1890. But, strange to say, the animals disappeared 

 from the pond at Littleton in the autumn of 1890, and have 

 never been found since in England. This was before the time of 

 preserved Rotifers, and no specimens, therefore, were left for 

 reference. But here again Mr. Shephard of Victoria has come 



* Communicated in connection with an exhibit of six mounted slides, 

 representing as many different species of Lacimilaria, January 19th, 1900. 



