448 The Annals and Magazine of Natural History. 



of radiata, (Echinodemata) . How many other classes it may therefore 

 be necessary to construct in order to include the whole, it would be 

 difficult to say. Mr. Gray's attempt to make us acquainted with the 

 numerous undescribed forms of these animals is, however, highly cre- 

 ditable to his zeal, as well as to his talents, and it is to be hoped that 

 in this difficult task, he will avoid the errors he has so justly con- 

 demned in Agassiz and others, of multiplying names unnecessarily, 

 where nomenclature is already so burdensome. 



There is also a short paper by Milne Edwards on the Affinities 

 of the Lepidosiren. This animal which belongs to America, was des- 

 cribed by Mr. Owen, after the most careful investigation as a fish, 

 was subsequently considered after an equally minute inquiry by M. 

 Bischoff, to be a reptile. M. M Edwards, after a careful investigation 

 of a specimen in the Jardin du Roi, Paris, inclines to the view adopt- 

 ed by M. Bischoff, as well from the presence of two auricles to the 

 heart, as from other points of structure too minute to detail in this 

 place. Several species of this curious form appear to be known, but 

 we still require to discover some intermediate species, presenting a 

 more decided character, which may reveal the true relations of the 

 group. 



The geological papers are less numerous than those of the de- 

 partments we have noticed ; they consist of two papers by Mr. Bow- 

 erman on the natural terraces of the Eildon Hills, the rocks composing 

 the acclivities of which are hollowed out into terraces of from 100 to 

 120 yards broad, ascribed to the effects of glaciers, according to the 

 views of Professor Agassiz. These views are fully entered into in 

 a communication from M. Agassiz himself in another part of the 

 volume extracted from the Proceedings of the Geological Society, 

 November 1840. M. Agassiz does not suppose that his views on 

 this subject will at once meet with the general concurrence of geolo- 

 gists, and admits, that the phenomena of glaciers in different lati- 

 tudes and altitudes will differ in their effects. Having devoted several 

 years to the study of these effects in Switzerland, M. Agassiz then 

 directed his inquiries to the investigation of appearances resembling 

 the effects of glaciers in countries in which such phenomena are 

 now unknown. The upper surface of glaciers approaches nearest 

 to the character of snow, and the lower surface to that of ice. Above 

 a certain elevation, the temperature is never high enough to melt 



