1844.] Farther observations on the Pondicherry Fossils. 151 



rocks — this consists of the cast of a single chamber of a very 

 large Ammonite — it is in a beautiful state of preservation, and 

 retains the foliated edges at the sides and the groove for 

 the siphuncle on the back, very distinctly marked — it is six 

 ipches in height and must therefore have belonged to a very 

 large shell, greatly exceeding in size any of those found at 

 Seedrapett. But this as will be shewn hereafter, is not the 

 only evidence which we possess that the deposit at Ootatoor 

 in Trichinopoly is to be described to an age of gigantic 

 Ammonites.* 



In a former number of this Journal Lieutenant Newbold 

 suggested that the fossiliferous beds of Pondicherry, probably 

 extended into the Verdachellum talook of S. Arcot. It was 

 long before I was enabled to obtain any positive evidence of 

 this fact, and it proves how little dependence can be placed 

 on Native evidence, that all enquiry among those who ought 

 to have been best acquainted with local circumstances, failed to 

 elicit the required information. Accident however subse- 

 quently established the correctness of Lieutenant New hold's 

 views and the sagacity with which he> had drawn his infer- 

 ences. Mr. Murray the Sub Collector of South Arcot in the 

 course of a ride about 6 or 7 miles from Verdachellam, ob- 

 served that the surface of the rock by the side of the road, 

 was marked with shells, and was kind enough to send me a 

 few specimens. It consisted of an impure limestone, con- 

 taining much earthy matter, and a number of bivalve shells, 

 resembling pectens of 2 or 3 species. One of these shells 

 closely resembles the Pecten Beaveri in Sowerby's Min. 

 Cone. II. P. 131 — another nearly resembles the Pecten quinque 

 costatas. I afterwards received a further supply of the rock, 

 but failed in obtaining from it any further variety of fossils. 



In November last however I was enabled to pay a short 

 visit to Verdachellum for the purpose of exploring the depo- 

 sit. The formation round Verdachellam struck me at first 



* I have also met with the teeth of fish in this formation.— B. C. 



