XV 



LACINULARIA SOCIALIS. 



A CONTRIBUTION TO THE ANATO:\IY AND PHYSIOLOGY OF THE 



ROTIFERA 



Transactions of the Microscopical Society of London, new series, vol. t. 1853, 

 //. 1-19. {Read December ■x,'^, 1851) 



The leaves of the Ceratopliylluin, which . abounds in the river 

 Aledway, a Httle above Farleigh Bridge, are beset with small trans- 

 parent, gelatinous-looking, globular bodies, about i-5th of an inch in 

 diameter. These are aggregations of a very singular and beautiful 

 Rotifer, the Lacinnlaria socialis of Ehrenberg. On account of their 

 relatively large size, their transparency, and their fixity, they present 

 especial advantages for microscopic observation ; and I therefore 

 gladly a\-ailed myself of a short stay in that part of the countrj' to 

 inquire someAA'hat minutely into their structure, in the hope of being 

 able to throw some light on the many doubtful or disputed points of 

 the organization of the class to which they belong. 



^^'e are told by Ehrenberg (Tnfusions-Thierchen,' p. 403) that 

 Lacinularia socialis was discovered and described anonymously in 

 Berlin in 1753. Miiller bestowed upon it the name of Vorticella 

 socialis, which was changed by Schweigger to Lacinulai'ia in 1820. 

 Previously to the time of Ehrenberg the genus appears to have 

 become confounded with Megalotrocha , and indeed Dujardin, very 

 reasonably, as it seems, altogether denies the propriety of their 

 .separation. The extreme resemblance of the two forms is admitted 

 by Ehrenberg himself; but he considers the attachment of the ova of 

 Megalotrocha by a filament to the body — a circumstance which does 

 not obtain in Lacinularia — and the existence of a gelatinous invest- 

 ment in the latter which is not found in the former, to be sufficient 

 grounds of distinction. 



The matter is not one of much importance, but I call attention to 



