Fossiliferous beds near Pondicherry. 235 



Many of these masses indeed bear a great resemblance to 

 pieces of old wood, although the ligneous structure is not 

 visible through a common lens, and I have not been able to 

 prepare a piece for examination under the microscope. 



Several portions of Hamites were also found, generally im- 

 bedded in the hard stone, and too imperfect to draw. 



It is not necessary to enter into a detailed description of 

 the shells figured in these drawings. Drawing I. fig. 4, is the 

 section presented by a spiral shell, which is found in consi- 

 derable numbers — the septa consisting of calcareous spar, 

 and the interstices being filled up with limestone. 



Some of the small shells figured in drawing II. bear much 

 resemblance to fresh-water species ; but such can hardly be 

 the case. Fig. 1 1 of this drawing appears to be an Inocera- 

 musj the hinge of the lower valve protruding considerably 

 beyond the upper. Fig 13 is a singular description of flat 

 bivalve. 



Drawing IV. Fig. 2, is evidently a Grypha. Fig. 5 is a 

 very common bivalve at Seedrapett, and is found in a very 

 perfect state. Fig. 4 is a much rarer shell. 



It will probably be admitted, that the facts recorded above 

 regarding this formation establish, beyond a doubt — 1st. that 

 the deposit is of marine origin ; 2ndly 5 that it is a secondary 

 and not a tertiary formation. The existence of the Baculite, 

 Ammonite, and Hamite appear to me to be conclusive on that 

 point, not to mention that almost all the shells which can most 

 readily be identified, correspond with fossils of the chalk.* 



The fossils, of which there are two very large collections 

 now at this place, besides many sets which have been sent to 

 friends taking an interest in the subject, were all found 

 either loose on the surface, or they were extracted from the 



* Baculite, Hamite, Ostrea carinata, Gryphcea, Inoceramus, Spatan- 

 gus, Trochus. (drawing III. Fig. 4.) I am not aware of there being any 

 well authenticated instance of either the Baculite or Ammonite being 

 found in a tertiary deposit. 



