CONTENTS. 



I. Description of the Organ of Voice in a new Species of IVild Swan (Cyg- 



nus Buccinator, Richardson). By William Yarrell, Esq., F.L.S. 8^ 

 Z.S. page 1 



II. Descriptions of three British Species of fresh-water Fishes belonging to 



the Genus Leuciscus of Klein. By William Yarrell, Esq., F.L.S. ^ 

 Z.S 5 



III. Observations on the Tropseolum pentaphyllum of Lamarck. By Mr. 



David Don, Libr. L.S 11 



IV. On the Adaptation of the Structure of the Sloths to their peculiar Mode of 



Life. By the Rev. William Buckland, D.D., F.R.S. F.L.S. F.G.S., 

 and Professor of Geology and Mineralogy in the University of Oxford. ) 7 



V. Observations on Naticina and Dentalium, two Genera of Molluscous Animals. 



By the late Rev. Lansdown Guilding, B.A., F.L.S. 29 



VI. Monograph of the East Indian Solaneae. By Christian Godfrey Nees 



von Esenbeck, M.D., F.M.L.S., President of the Imperial Academy 

 Naturce Curiosorum, and Professor of Botany in the University of Bre.s- 

 lau 3/ 



