652 
the public, but I may be excused from announcing, that the mo- 
ment I exhibited to Professor Asmus some drawings of the Scottish 
old red sandstone fishes, his eye at once fell upon the Pterichthys 
as probably the type in miniature of an enormous creature, five 
times the dimensions of our largest specimens, which is found in 
rocks on which the University of Dorpat is situated. Anxious 
that we should no longer be without some representatives of these 
Palzo-ichthyolites, whose bones are so gigantic that they were 
formerly supposed to belong to mighty Saurians, I requested Dr. 
Asmus to prepare casts of them, which he has obligingly executed, 
and of these I now present a set to the Society, as one of the fruits 
of distant comparison resulting from my Russian travels, and as a_ 
memento of the instructive researches of Professor Asmus. With 
the mere announcement, however, of these mighty fishes I must now 
take leave of the animals of primeval days, by saying that the car- 
boniferous fossils of Russia are most singularly in accordance with 
those types which have been so ably elaborated by Mr. Phillips, Mr. 
Sowerby, and other geologists in our own country, a point to which 
I hope to call your attention at the next Anniversary. 
SECONDARY ROCKS. 
Pursuing the inquiry in the ascending order, the long period 
which is specially marked by the presence of gigantic reptiles is 
now before us. It commences with the magnesian limestone (the 
Zechstein and associated rocks), and terminates with the cretaceous 
system. In this wide field Professor Owen has taken the lead as a 
palzontologist, and will shortly lay before the world the results of 
his researches into the extinct Saurians of our island. Of this 
work I cannot speak, but from the knowledge we possess of Pro- 
fessor Owen's consummate acquaintance with comparative anatomy, 
and of his wonderful ability in detecting the minutest character in 
masses of bones obscured by matrix and mutilated by accident, we 
may anticipate that this work will enjoy the proud distinction of 
becoming a text-book with every natural philosopher in every part 
of the world. The points of this great inquiry to which he has 
called our attention during the last year, are the teeth and ske- 
letons of five species of his newly-formed genus Labyrinthodon, 
found in the new red sandstone of Warwick; the whole of which, 
after a most elaborate comparison with all collateral and congenerous 
forms of different families of reptiles, he proves to belong to Batra- 
chians, but with striking and peculiar affinities to the higher Sauria. 
From the evidence afforded by the comparative dimensions of one 
species of Labyrinthodon found in the same quarry, Professor Owen 
likewise shows that the anterior and posterior extremities must have 
been of disproportionate magnitude, according well with those of 
the Cheirotherium, and he therefore infers, and with great apparent 
justness, that the Labyrinthodon and the Cheirotherium were one 
genus. In a second memoir upon certain remains from the Oolitic 
Series, he has established a genus of Saurians equa! in size to the 
whale, and in a third upon the remains of a crocodilian Saurian 
