PERSISTENT TYPES OF LIFE 387 



animal life.* He stated, on the authority of Dr. Hooker, 

 that there are Carboniferous plants which appear to be 

 generically identical with some now living ; that the cone 

 of the Oolitic Araucaria is hardly distinguishable from that 

 of an existing species ; that a true Pinus appears in the 

 Purbecks, and a Juglans in the Chalk ; while, from the 

 Bagshot Sands, a Banksia, the wood of which is not dis- 

 tinguishable from that of species now living in Australia, 

 had been obtained. 



Turning to the animal kingdom, he affirmed the tabulate 

 corals of the Silurian rocks to be wonderfully like those 

 which now exist ; while even the families of the Aporosa 

 were all represented in the older Mesozoic rocks. 



Among the Molluska similar facts were adduced. Let 

 it be borne in mind that Avicula, Mytails, Chiton, Natica, 

 Patella, Trochus, Discina, Orbicula, Lingula, Rhynchonella, 

 and Nautilus, all of which are existing genera, are given 

 without a doubt as Silurian in the last edition of Siluria ; 

 while the highest forms of the highest Cephalopods are 

 represented in the Lias by a genus, Belemnoteuthis, 

 which presents the closest relation to the existing 

 Loligo. 



The two highest groups of the Annulosa, the Insecta 

 and the Arachnida, are represented in the Coal, either by 

 existing genera, or by forms differing from existing genera 

 in quite minor peculiarities. 



Turning to the Vertebrata, the only paleozoic Elasmo- 

 branch Fish of which we have any complete knowledge 

 is the Devonian and Carboniferous Pleuracanthus, which 

 differs no more from existing Sharks than these do from 

 one another. 



Again, vast as is the number of undoubtedly Ganoid 

 fossil Fishes, and great as is their range in time, a large 

 mass of evidence has recently been adduced to show 

 that almost all those respecting which we possess sufficient 

 information, are referable to the same sub-ordinal groups 

 as the existing Lepidosteus, Polypterus, and Sturgeon ; 

 and that a singular relation obtains between the older 

 and the younger Fishes ; the former, the Devonian Ganoids, 

 being almost all members of the same sub-order as 



* See the abstract of a Lecture " On the Persistent Types of 

 Animal Life," in the Notices of the Meetings of the Royal "institu- 

 tion of Great Britain. June 3, 1859, vol. iii. p. 151. 



