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 Iguanodon 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, — Description of Calamoichthys, a new Genus of Ganoid 

 Fish from Old Calabar, Western Africa. By John Alexander 

 Smith, M.D., F.R.C.P.E. ; with Observations on the Internal 

 Structure, by R. H. Traquaib, M.D., Demonstrator of Ana- 

 tomy in the University of Edinburgh*. 



In the beginning of January 1865, the author received from the 

 Rev. 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 32nd March, 

 1865, and stated that they were allied to the genus Polypterus ; 

 but from various difi'erences in character, to be afterwards de- 

 tailed, and especially the great relative length of their bodies, 

 and the apparently total absence of ventral tins, 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. 



