Chap. I. FOSSIL TURTLES. 305 



those of the Old red of Captain Brickenden, accepted by Lyoll and Mantoll, nor 

 those of the Rev. Dr. Duncan, examined and described hy Dr. Buckland, have 

 the shghtest resemblance to the tracks of any hving Reptile, wliile the bones of 

 the Devonian from Caithness, referred to Trionyx by Cuvier, and those of the 

 same formation referred to the same genus by Kutorga, are really Fishes, and 

 those of the Triasic period, described by Cuvier, are Reptiles of another order. 

 The first genuine Testudinata known among the extinct representatives of the 

 class of Reptiles, in past ages, belong to the oolitic series. 



It is self-evident, that the geologist who lias neither the means nor the incli- 

 nation to test critically how far any identification of fossils may be relied upon, 

 must, at every step, be led to the strangest conclusions. What would be the 

 direct inference, with respect to the plan of creation, to be drawn from the 

 presence of unmistakable Turtles in the oldest fossiliferous rocks ? Of course, the 

 conclusion would be that there is no kind of progressive order in the successive 

 appearance of Vertebrates upon the surface of our earth, since the presence of the 

 highest Reptiles would appear coeval with that of the oldest Fishes. But let it be 

 understood that all the supposed cases of the occurrence of Reptiles prior to the 

 Jura which have been quoted from time to time, cannot be relied upon, and are 

 evidently mistakes, the whole question at once changes its aspect, and w'e see 

 again an intelligible plan in the order in which organized beings have successively 

 made their appearance upon this globe. 



The following diagram, made, so far as it has been in ni}^ power, with the 

 same critical method with which I have scrutinized the case of Turtles, may give a 

 more definite idea, not only of the time of the first appearance of Testudinata, but 

 of their relations to their predecessors, their contemporaries, and their succes.sors 

 upon the earth.' It shows conclusively, that the four great branches of the 

 animal kingdom have had simultaneously representatives from the very beginning 

 of the existence of organized beings. It shows further, that the law which 

 obtains in the gradation and successive appearance of the Radiata, MoUusca, and 

 Articulata is not the same as that of the Vertebrata. For while the classes of 

 the first three branches appear all at the same time in the lowest fossiliferous 

 rocks, with the sole exception of Insects, there is a decided gradation among the 

 classes of Vertebrata. Among Radiata, we find simultaneously in the lowest 

 rocks, Polyjii and Echinodenns. The absence of remains of Acalephs in the 

 oldest rocks is no objection to this assertion, when we remember how soft and 



* III onliT lo appreciate fully the meaning of this also sections 21-28, from page 03 to 123, where many 

 tahic, it would 1)(' well, while considering it in detail, points are considered, which here are repre.sonted 

 to read section 7 of the first chapter, page 23, and graphically. C'onip. also Chap. 3, p. 181-187. 



39 



