Correspondence — Prof. Phillips. 239 



AGE OF THE EOCKS OF ALASKA TERRITORY. 

 Sir, — Mr. Dall appears to me, in the extract of a letter of Ms, pub- 

 lished in your last number, to base his determination of the Alaska 

 beds upon a species of Platanus found near Topanica, which he con- 

 considers to be undoubtedly Miocene. I fear this cannot be accepted 

 as settling the question, seeing that Professor Heer has described a 

 species of this genus (P. Newherryana), from Nebraska, found in strata 

 which he originally considered to be Miocene, but which Prof. New- 

 berry has lately shown from the raolluscan remains to be Cretaceous. 

 Some additional evidence must be found before the age of these beds 

 can be definitively fixed. The remarkable persistence of some 

 of the generic forms of America from the Secondary down to the 

 existing flora, as lately expounded by Professor Newberry, is a fact 

 of great importance, especially when contrasted with the changes 

 which have taken place in the Secondary and subsequent floras of 

 Europe. W. Cakruthers. 



THE OLDEST BRITISH BELEMNITE. 



Sir, — The interesting notice by Mr. Tate, of his " little old " 

 Belemnite from the Lower Lias beds, which yield Ammonites angu- 

 latus, may be a fit occasion for entreating the renewed attention of 

 Palaeontologists to the importance of this kind of research, unpro- 

 mising though it be, for the origin of the " geno." My friend, Mr. 

 C. Moore, besides placing at my disposal his whole collection of 

 Belemnites, has sent me, among other rarities, a very small conical 

 specimen from beds immediately above those which yield Ostrea lias- 

 sica. This may be the young of the short conical form to which I 

 have given the name of Belemnites calcar (Monograph of Belemni- 

 tidce, pi. 11, fig. 4). The fossil described by Mr. Tate must certainly 

 be distinguished from every variety of Belemnites clavatus ; regarded 

 as a young individual, it may with some confidence be thought likely 

 to prove to be closely allied to B. pencillatus, which is by no 

 means always deprived of lateral furrows, and is, in fact, a variable 

 species (Monograph of Belemnitidce, pi. 1., fig. 2, p. 35). I possess 

 specimens of JL acutus and B. pencillatus, from the Lower Lias of 

 Antrim. Belemnites dorsalis, of the Yorkshire Upper Lias, is cer- 

 tainly quite distinct. John Phillips. 



Oxford, April 4, 1869. 



THE OLDEST BRITISH BELEMNITE. 

 Sir, — Mr. Tate's "oldest British Belemnite," described in the 

 April number of the Geological Magazine, will have to yield the 

 palm to an older one, which I found some years ago in the Insect 

 beds {Ammonites planorhis zone of some geologists) at Binton, in 

 Warwickshire. My friend Professor Phillips supposed tliat no 

 Belemnites were known so low down, and I at once forwarded the 

 specimen to him, and it is still in his possession. Unfortunately it 

 is a mere fragment, consisting only of the phragmocone or cliambered 

 part of the shell, without the attached guard or sheath. The cham- 

 bers, though crushed, from their size, indicate a tolerably large 



