128 CRETACEOUS ROCKS OF S. INDIA. [PaRT II. § 1. 



notably- N. Bouchardianus, N. Clementinus and JV. Danicus. The 

 occurrence of this last (in the highest beds only in Trichinopoly,) is 

 remarkable, not only in the mere fact of its occurrence, but also in its 

 association with an Ovulum, and a fauna having as much of a Tertiary 

 as of a Cretaceous aspect, and peculiar to the beds in question. It 

 is true that at Valudayur, near Pondicherry, N. Danicus occurs 

 in the lowest beds of the group, as also do the Ovulum, N Bou- 

 chardianus and Tiirritella monilifera, with other forms occurring 

 in the lower part of the Arrialoor group, but from the way in which 

 „ „ ., all the Arrialoor beds thin out to the North 



Intermixture ot lossiis 



at Pondicherry. j ^^[^[^^ [^ probable that for long periods little or no 



sediment was deposited on this part of our area, so that a thickness of a few 

 feet at this spot may represent as many hundreds of feet in area of 

 more abundant deposition in Trichinopoly, and thus fossils may, in the 

 absence of sections, appear to be mingled together, which, in Trichino- 

 poly, occur in distinct and widely separated bands. 



Hamites, Baculites and possibly Turrilites re-appear in the lower 

 part of the Arrialoor group, having been nearly or entirely absent from 

 the Trichinopoly deposits, and Radiolites of more than one species are 

 extremely abundant at a particular zone ; Squaloid teeth (Lamna, &e.,) 

 are found in some of the lower beds, as also in the same formation at 

 Pondicherry, but the most remarkable and interesting occurrence is that 

 of remaias of the Megalosaurus, a reptile which in Europe has not been 

 found to range above the Wealden formation. These remains, which 

 I shall describe more fully further on, consisted of bones, (in so bad 

 a state of preservation, however, as to have little recognizable form,) 

 and one tooth, upon the discovery of which the identification of the 

 reptile therefore rests. 



Fossil wood is not uncommon in the fossiHferous beds of the Arrialoor 

 group, but is less abundant than in the Trichinopoly beds. Its nature 

 I have not ascertained. 



