INTRODUCTION. XXV 
several genera appeared for the first time during the early part of this period; but 
there is nothing to indicate any great phytological break between the two widely- 
separated systems—the Carboniferous and Triassic. If it be correct, as stated, that 
Cycadeous Gymnosperms occur in the Coal-measures of Bohemia, and a species of 
Temopteris (T. Eckhardt) in the Mansfeld Kupfer-schiefer, it will follow, that the 
Deuterozoic period is not so much distinguished from the Protozoic by any peculiarity 
of its great phytological groups. Generically these periods are related to each other : 
they are also, to a certain extent, specifically connected: it may, therefore, be fairly 
concluded, that the Permian Flora did not differ to any material extent from either the 
Carboniferous, or the Triassic. 
Of the animal sub-kingdom adiata, little can be predicated. ‘The Polyparians of 
the Triassic rocks are confessedly too little known to be referred to. The Echino- 
derms are in the same category. Cyathocrinus ramosus, Archeocidaris Vernewliana, 
and the Corals, however, give the Permian Radiata a Carboniferous aspect. 
Referrmg to the class Crustacea, the abundance of Trilobites in the Carboniferous 
rocks forms a striking contrast to their marked absence in the Permian, and all 
subsequent formations: in this point of view, the Permian system possesses a negative 
deuterozoic aspect; while Kutorga’s Limulus oculatus gives it a positive secondary 
organic facies: the connexion, however, between the Permian, and Carboniferous 
systems is still maintained by means of the Coal-brook Dale Xiphosurians. 
The Molluscous sub-kingdom binds together the Carboniferous, Permian, and 
Triassic systems. Several species of the Carboniferous period continued to live, or 
were closely represented, in the Permian; and a few appear to have had their 
existence prolonged into the Triassic. There is a strong generic and a faint specific 
relation running through the three systems ; but taking all the classes into consideration, 
especially the Palliobranchiate, the relation has obviously more of a Protozoic than a 
Deuterozoic character. 
As already observed, it is doubtful whether any of the Permian fishes have been 
found in the Carboniferous rocks: apparently, then, the Permian system is specifically 
distinct from the Carboniferous in its Ichthyan relations: generically they are 
connected with each other; and in this respect the connexion is a very close one. 
This cannot be so confidently asserted of the Permian, and Triassic systems ; though 
the occurrence of heterocercal Goniolepidots in the Trias rocks near Coburg,—Sir 
Phillip Egerton’s fortunate discovery of the Pycnodont characters of Platysomus,— 
and the presence of the homocerque Zetragonolepis Murchisont in the Permian rocks 
of Russia,—approximate the fishes of the two systems more closely than was admitted 
a few years since. 
We cannot as yet form any satisfactory conclusion—as to whether the Permian system 
is more related to the Carboniferous than to the Triassic, in its reptilian fauna. The 
occurrence of Labyrinthodons and Rhynchosaurs in the Triassic rocks, and, according to 
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