118 -^ CRETACEOUS ROCKS OF S. INDIA. [PaRT II. § 1. 



them measuring 85 feet in length, and having been originally, as is evidenced by its impression. 

 Fig. 13. Loo of Silicified Wood near Moulvoy. 



of three times that length, is repressnted in the accompanying figure, imbedded in these 

 semi-consolidated sands, and exhibiting at one end the basis of its roots or branches, which 

 measured altogether 3 feet in diameter, and resembled those of a Dicotyledonous tree. The 

 structure was by no means clear. Another trunk that I measured by pacmg was not less than 

 about 60 feet long. 



The sands frequently exhibit an internal false-bedded structure in great perfection; the 

 layers having on the whole a predominant dip to the Eastward. These granitic sands and gravels 



Fossil beds North of Serda- with silicified w ood extend about a mile to the North of Serdamun- 

 mungaium. galum, where their lower beds are intercalated with shales aiid 



limestone beds of undoubted Trichinopoly age, as evidenced by numerous fossils, such as Nauti- 

 lus elegans, D'Orb., A. Tamulicus* n. s., Slrombus (allied to but distinct from S. contortus, 

 Forbes), Fimis excavatus* n. s., Ghemnitzia undosa, Pyrula, fee, all characteristic species, 

 A. Pinna is very abundant here ; also a large species of Oj)is, one of Cyprina and several 

 species common to the Trichinopoly and Arrialoor groups. 



The lower beds of the group, between Garoodamungalum and Annapaiidy, exhibit much the 



, -.-r .,. i> ^ same character as batween the former place and Alundanapuram, 



Lower beds North of Garoo- ^ ^ e 1 



damungalum. and the fossil contents are very similar. Ammonites and Nautili 



become abundant in the neighbourhood of Annapaudy, and in the ravines around, and specially 

 to the East of the village, fine specimens of A. Gaittama, Forbes, A. Tamulicus, n. s.,* A. Rho- 

 fomagensis ? and some other spscies are found in large nodules in the shales, many of the 

 specimens measuring between 1 and 2 feet in diameter. Nautili of two species are also common 

 with Spondylus, Ostrea, Pecten [.5-costatus ?], Inoceramus, Pholadomya, and Cerithium, and frag- 

 ments of fossil wood, in all casas bored by the Teredo. The univalves and bivalves characteristic 

 of the limestone South of Garoodamungalum are here chiefly confined to the bottom beds ; 

 where tbey are, however, not very abundant, many of tbe limestone bands being unfossilifei'ous 

 or containing "only a few scattered specimens of Ghemnitzia undosa. These fossils re-appear to 

 some extent in the highest beds close to the boundary of the Arrialoor group. 



* M.S.S. sp. 



