48 NEW WORKS IN NATURAL HISTORY. 



with transverse slight corrugations, as if the animal, between 

 the efforts of progression, had rested its belly on the ground, 

 a constant character with reptiles, but not with mammals. — 

 The long, recurved, angular claw seen distinctly on the sup- 

 posed posterior thumb, as on the other hind toes of the Chi- 

 rotherium, is crocodilian, and not mammiferous ; it is obvious 

 on the rudimentary outer toe of alligators, but was never seen 

 on the opposable hind thumb of an opossum. In the foot- 

 marks you perceive that the heel of the hind foot has pressed 

 heavily on the ground, and raised much of the sand around 

 it, as in the heavy-bodied and feeble-footed reptiles, and that 

 it was not able to raise itself on tip-toe, and sink its claws 

 into the ground, like the more active and vigorous unguicu- 

 lated quadrupeds. The terminal tapering of the hind toes of 

 this animal into the large, broad, conical claws, is crocodilian 

 in its character, and most unlike the sudden setting-on of 

 these parts on the rounded toes of quadrupeds ; so that, al- 

 though these relics, of vast antiquity in the histoiy of our 

 globe, are full of scientific interest, and may long exercise the 

 acumen of naturalists, they do not appear to me to have yet 

 satisfactorily established the existence of hot-blooded mam- 

 miferous quadrupeds at the remote period assigned to the de- 

 position of this new red sandstone. They show that notwith- 

 standing the extremely perishable character of all organic de- 

 posits committed to those porous siliceous beds, percolated 

 incessantly by water, they are capable of preserving, for an 

 indefinite period, impressions thus mechanically made upon 

 their surface, and of transmitting entire, to the remotest pos- 

 terity, the most delicate footmarks of animals, every other 

 trace of whose existence has long been effaced from our 

 globe. 



Among the promised forthcoming Works on Natural His- 

 toiy or general science, w^e may mention ' A History of the 

 Fishes of Madeira, 7 by the Rev. R. T. Lowe ; in which the 

 author will have the able assistance of Miss M. Young, in de- 

 lineating the species. The admirable sketches made by this 

 lady which illustrate Mr. Lowe's already published ichthyolo- 

 gical memoirs in the ' Transactions of the Zoological Society,' 

 lead us eagerly to anticipate the appearance of this more ex- 

 tensive undertaking. 



Mr. Edward Newman announces an illustrated ' History 

 of British Ferns': and the editor of the 'Arcana of Science' a 

 scientific annual, entitled ' The Year-Book of Facts.' 



