THE CARBONIFEROUS PERIOD. IQI 
them very small, but others attain comparatively gigantic 
dimensions, though all fall short in this respect of the huge 
examples of this group which occur in the Trias. One of the 
largest, and at the same time most characteristic, forms of the 
Carboniferous series, 1s the genus Azthracosaurus, the skull of 
which is here figured. 
No remains of true Reptiles, Birds, or Quadrupeds have as 
yet been certainly detected in the Carboniferous deposits in 
any part of the world. It should, however, be mentioned, 
that Professor Marsh, one of the highest authorities on the 
subject, has described from the Coal-formation of Nova Scotia 
certain vertebree which he believes to have belonged to a 
marine reptile (Hosaurus Acadianus), allied to the great 
Ichthyosauri of the Lias. Up to this time no confirmation 
of this determination has been obtained by the discovery of 
other and more unquestionable remains, and it therefore 
remains doubtful whether these bones of Hosaurus may not 
really belong to large Labyrinthodonts. 
LITERATURE. 
The following list contains some of the more important of the original 
sources of information to which the student of Carboniferous rocks and 
fossils may refer :— 
(1) ‘Geology of Yorkshire,’ vol. ii. ; ‘The Mountain Limestone Dis- 
trict.’ John Phillips. 
(2) ‘Siluria.’? Sir Roderick Murchison. 
(3) ‘Memoirs of the Geological Survey of Great Britain and Ireland.’ 
(4) ‘Geological Report on Londonderry,’ &c. Portlock. 
(5) ‘ Acadian Geology.’ Dawson. 
(6) ‘Geology of Iowa,’ vol. i. James Hall. 
(7) ‘Reports of the Geological Survey of Illinois’ (Geology and Pale- 
ontology). Meek, Worthen, &c. 
(8) ‘ Reports of the Geological Survey of Ohio’ (Geology and Palzon- 
tology). Newberry, Cope, Meek, Hall, &c. 
(9) ‘Description des Animaux fossiles qui se trouvent dans le Terrain 
Carbonifére de la Belgique,’ 1843 ; with subsequent monographs 
on the genera Productus and Chonetes, on Crinoids, on Corals, 
&c. De Koninck. 
(10) * Synopsis of the Carboniferous Fossils of Ireland.’ M ‘Coy. 
(11) ‘ British Palzeozoic Fossils.” M ‘Coy. 
(12) ‘ Figures of Characteristic British Fossils.’ Baily. 
(13) ‘Catalogue of British Fossils.’ Morris. 
(14) ‘Monograph of the Carboniferous Brachiopoda of Britain’ (Palzeon- 
tographical Society). _ Davidson. 
(15) ‘ Monograph of the British Carboniferous Corals’ (Palzeontographical 
Society). Milne-Edwards and Haime. a 
(16) ‘Monograph of the Carboniferous Bivalve Entomostraca of Britain’ 
(Palzeontographical Society). Rupert Jones, Kirkby, and George 
S. Brady. 
