33G Horner's Geological Address. 



have done more than any other palaeontologists to prove the 

 progressive and undistinguishable blending of eocene into 

 miocene, and this into pliocene, by the mammalian fossils, and 

 have shewn that some species of reptiles actually exist at the 

 present day which were coeval with the Himalayan Anoplo- 

 there, Mastodon, and Hippopotamus. 



The attention of several distinguished naturalists has lately 

 been directed to the investigation of the structure and clas^ 

 sification of Trilobites. A valuable work on these singular 

 extinct Crustacea has been lately given to the world by Pro- 

 fessor Burmeister, who is now revising an English translation 

 of it, to be published by the Ray Society. In this work there 

 is a systematic arrangement of all the species known to the 

 author, and there are dissertations of great value on their or- 

 ganization. M. Emmerich has also published a very impor- 

 tant memoir on the structure of Trilobites, a translation of 

 which has lately appeared in Mr Taylor's " Scientific Me- 

 moirs." In Sweden, Professor Loven, a naturalist distin- 

 guished for his researches among the invertebrate animals, 

 has commenced the investigation of the Trilobites of that 

 country with great success. His papers may be found in the 

 Proceedings of the Swedish Academy for 1844 and 1845. All 

 the memoirs now enumerated are illustrated by excellent 

 plates. Lastly, in the " Geology of Russia" will be found an 

 interesting note on the affinities of Trilobites, by Professor 

 Milne Edwards. 



In what I have said of the accession during the last year 

 to our knowledge of the Devonian rocks, I have referred to 

 the Monograph by M. Agassiz of the Fishes of the Old Red 

 Sandstone, which those most capable of appreciating its value 

 consider as one of his most important works ; and I have 

 reason to know that he himself views it in that light. I again 

 refer to it in this place on account of some peculiar views there 

 developed, which I do not find altogether assented to by those 

 whose judgments on this subject are much looked up to. 



M. Agassiz states, p. xxx., " que les poissons de I'Old Red 

 representent, par leur structure toute particuliere, I'age em- 



