Geological Society, 479 



L'lmosa melanura, Leisl. Very common; but the Limosa nifa 

 (Briss.) is not found here. 



Scolopax Rusticola, Linn. Abounds in the hills. 



Gallinago, Linn. Not rare. 



GaUinula, Linn. Not rare. 



Tringa pugnax, Linn. Common. 



subarquata, Temm. Tolerably common. 



Temmincki, Leisl. Very common. 



minuta, Leisl. Very common. 



Phalaropus platyrhynchus, Temm. Rare. 

 Tadorna rutila, Steph. Common. 



Bellonu, Steph. Verj' rare. 



Anas clypeata, Linn. Moderately common. 

 ChauUodus Strepera, Swains. Moderately common. 

 Dafila acuta, Linn. Common. 

 Querquedula circea. Very common. 



Crecca. Very common. 



Mareca Penelope, Selb. Not common. 

 FuUgula rufina, Steph. Very common. 



Nyroca, Steph. Very common. 



cristata, Steph. Not common. 



ferina, Steph. Not common. 



GEOLOGICAL SOCIETY. 



June 1 5, 1 842. — A communication was made by Dr. Grant, F.G.S., 

 " On the Structure and History of the Mastodontoid Animals of 

 North America." 



The chief object of this communication was to point out the 

 structural differences and zoological distinctions of the Mastodons 

 and Tetracaulodons of North America ; and the inquiries were in- 

 stituted in consequence of the favourable opportunity afforded by the 

 temporary exhibition, in this metropolis, of Mr. Koch's large collec- 

 tion of organic remains from the State of Missouri, consisting prin- 

 cipally of the relics of these two genera. 



After pointing out the important applications of the study of these 

 remains, and the geological relations of Mastodontoid animals, and 

 the discordant opinions of zoologists as to their specific distinctions. 

 Dr. Grant entered into extended details regarding the general struc- 

 ture and the peculiarities of the skeleton in the three principal 

 Mastodontoid genera, Mastodon, Tetracaulodon, and Deinotherium, 

 which are compared with those of the elephant and other allied ge- 

 nera. The fifth section of the memoir is occupied with the descrip- 

 tion of the development, forms, structure and changes of the dental 

 system of Mastodontoid animals ; and each tooth and tusk of the 

 three principal genera are described and compared, and the principal 

 modifications they exhibit according to difference of age, sex, and 

 species. After pointing out the necessity of including the entire se- 

 ries of successive teeth, in the dental formulae of genera, where the 

 teeth are constantly displacing and succeeding each other through 



