112 Dr. J. A. Smith on Calamoichthys, 
meridge Clay, or even Coral Rag, so stored with phosphoric 
acid that its denudation would furnish nothing but a magnificent 
crop of nodules of phosphate of lime, like these. 
The wood which occurs in the bed is like that which occurs 
in the Gault of the southern counties and Carstone here, and is 
mineralized with phosphoric acid, and therefore no more requires 
an appeal to extensive denudation of Purbeck beds to account 
for it than the occurrence of remains of [guanodon can be held 
to prove denudation of Wealden beds ; for the chief fame of that 
beast is from its occurrence in the Shanklin Sands in the Igua- 
nodon quarry. 
Like the Cambridge Greensand, the deposit offers many new 
facts of interest in the distribution of life. Thus Pliosaurus, so 
characteristic of Oxford Clay, Coral Rag, Kimmeridge Clay (and 
probably Portland), is now found in the approximate equivalent 
of the Shanklin Sands. Dinotosaurus, a new genus of the 
Oxford and Kimmeridge Clays, also abounds here, and thus, 
like Ichthyosaurus, Plesiosaurus, Megalosaurus, &c., helps to con- 
nect into one great life-system the lower and the upper Secondary 
Rocks. 
I am, Gentlemen, 
Sidney Sussex College, Cambridge. Faithfully yours 
July 17, 1866. H. SEELEY. 
XXI.—Deseription of Calamoichthys, a new Genus of Ganoid 
Fish from Old Calabar, Western Africa. By Joun ALEXANDER 
Smitn, M.D., F.R.C.P.E.; with Odservations on the Internal 
Structure, by R. H. Traquair, M.D., Demonstrator of Ana- 
tomy in the University of Edinburgh*. 
In the beginning of January 1865, the author received from the 
Rey. Alexander Robb, Old Calabar, a package of specimens of 
natural history preserved in spirits. Among these were two 
small ganoid fish. They were, however, imperfect, having been 
torn across near the anal region, and their caudal extremities were 
wanting. The characters of the fish could not, therefore, be 
completely determined. The author, however, exhibited them 
at a meeting of the Royal Physical Society, on the 22nd March, 
1865, and stated that they were allied to the genus Polypterus ; 
but from various differences in character, to be afterwards de- 
tailed, and especially the great relative length of their bodies, 
and the apparently total absence of ventral fins, he would place 
them in a new genus, which, from their general aspect and form, 
* Communicated by Dr. Smith, from the Proceedings of the Royal 
Society of Edinburgh. 
