Chap. VIL] trichinopoly district — trichinopoly group. 117 



Fusus, Murex, and Pyrula as yet unnamed ; Voluta TrichinopoUtensis, Forbes, and another 

 allied species* ; Chemnitzia -undosa, Sow., Turritella moniUfera,f Forbes, and T. Soiverbii, 

 Forbes ; Natica suturalis, Sow., and two or three other species of the same genus , 

 and one or two species of Hostellaria. Of the Conchifera the most numerous species 

 are Area TrichinopoUtensis, Forbes, Area abrupta, Forbes, and another small species, 

 Cardium altum, Sow., C. Jlillamcm, Sow., C. incompiiim, Sow., and an unnamed species. 

 Ve}iiis Areotensis, Forbes, and other smooth species ; Artemis lenticularis, Forbes ; and 

 Astarte planissima, Forbes : also a large Mya-like bivalve. A few Ammonites occur also in the 

 limestone, but they are by no means abundant. Fossil wood in the form of water-worn 

 logs, much bored by Seredo, occurs in some of the lower beds in the neighbourhood of 

 the Alundanapuram nullah. One of these measured 7 feet long, and 1 foot in diameter 

 and a mass of fragments close by, and the impression on the matrix showed that it was 

 originally at least of twice this length. Another log that I measured was not less than 

 20 feet long. The same bed is fuU of large pebbles of gneiss and hornblendic schist (from 

 Seraganoor), some of the pebbles measuring as much as 6 or 7 inches and 1 foot in diameter. 



In the continuation of one of the limestone beds to the East of Alundanapuram, I found 

 some E.isso3e unassociated with any other fossil, except Cytherea, and close by Mr. Foote 

 procured a few Pycnodont-teeth, the only fish remains, with one exception, met mth in the 

 Trichinopoly group. In a bed of shale intercalated in the white sands above the Rissoa band, 

 I noticed also some traces of plant remains, among which one of my colleagues discovered 

 what appeared to be a Zamia, but the specimen was in bad condition, and I felt sooiewhat 

 uncertain of its identity. 



To the North of the Alundanapuram nullah, limestone beds are exposed in the broken 



Kullah section continued. ^"^^"l' ^^PP^^§ ^^«^* ^^ *° ^^^^ by South. Some of them are 



marked extensively with what appear to be fucoid impressions, 

 and others with what are undoubtedly worm tracks crossing and re-crossing each other 

 as nearly to cover the sui-face of the bed. 



Passing up the nullah across the strike of the beds, the latter are seen dipping at angles 

 of not more than 3° or 5° to the East by South and South-east. Masses of fine, brown laminated 

 sand, or argillaceous sands, with shales and occasional limestone bands, succeed, the bedding 

 tolerably persistent and regular, up to the ridge which forms the local watershed between 

 Alundanapuram and Moulvoy, after crossing which we meet with the ii'regular beds of sand 

 shale, conglomerate, &c., described in a previous page. Ammonites and Nautili begin to 

 appear in the concretions and shales of these higher beds, and are tolerably abundant in the 

 Beds at Serdamungalmn. broken ground to the West of Serdamungalum. At this spot I 



found A. Gautama, Forbes., A. Mantelli, or an allied species, 

 and Nautilus elegans, D'Orbigny, which is one of the most characteristic species of the Trichi- 

 nopoly group. Fossil woDd is tolerably abundant in the shales, but in small fragments only. 

 The shales are here succeeded by a mass of white granitic sands and gravels, the upper 

 Sands -with siUcifled wood. parts of which are of doubtful age, forming indeed the passage into 

 ^^ ""^ ' ■ the Arrialoor group ; and in these large logs of silicified wood 



are imbedded in a prostrate position, and quite untouched by the Teredo, a fragment of one of 



* The names of these fossils are quoted from Forbes's Monograph. 



t This species occurs also abundantly at the base of the Arrialoor group near Pondicherrv. 

 I have not met with it in the Arrialoor beds of Trichinopoly. 



