1822.] Geology of the Isle of Wight, S^c. ^35 



(4.) Trigonia. 



(a.) DcEclalea. Min. Con. pi. 88. 



lb.) Alaformis. Min. Con. i^l. 215. 



Both species are found in lied- cliff reef. Casts? of the latter 

 abound in the ferruginous beds ofShankHn Chine. It is very 

 common in the green sand formation. 



(5.) Astarte excavata (?) Min. Con. pi. 233. Red-cliff reef. 



(6.) Sphrera corrugata. Min. Con. pi. 335. Red-clifF reef. 



(7.) Terebratula. Too much imbedded to exhibit specific 

 characters. Resembles terebratula pectita. It exists in great 

 abundance, and in various states of preservation, in some beds 

 near Shankhn Chine. 



(8.) An exceedingly minute oval-shajoed bivalve. It exists ia 

 immense abundance, often appearing like a thin farinaceous 

 coating interposed between the laminae of calcareous slate clay, 

 which occur in the argillaceous beds of Sandown Bay, and 

 various other parts of the formation. 



(9.) A bivalve abounding in the thin beds of limestone which 

 occur in so many parts of the formation. Casts of the same 

 shell are common in some of the less indurated beds. We were 

 in no instance able to obtain specimens with distinct specific 

 characters. 



(10.) To this hst may be added the casts of four or five spe- 

 cies which are in too imperfect a state to be ascertained. From 

 the upper part of the chft' near Shanklin Chine. 



5. Vertebral Bones, Fins, Sec. of a small Fish. — In 

 great abundance in some impure calcareous beds, west of Brook 

 Point. To these we may add the bones of a large cetaceous 

 animal which were found, as I have been informed by Pro- 

 fessor Buckland, in Sandown Bay. 



The preceding list, however imperfect, will show that the 

 iron sand is by no means destitute of fossil inhabitants. They 

 are generally in a bad state of preservation, and little inviting to 

 the collector. But on this very account, the few beds which 

 exhibit them in a state sufficiently perfect for description are the 

 more deserving of a minute examination. 



III. Tetsworth Clay. 



This bed, interposed between the green sand and the iron sand, 

 is perfectly continuous in the Isle of Wight.* It is of compara- 

 tively httle interest, inasmuch as it contains very few fossils. In 

 the ruinous cliff formed by its western termination, we found 

 fragments of a thin calcareous bed containing traces of a small 

 species oivivipara. This fact, if confirmed by better specimens, 

 would be interesting, because shells of the same genus abound 

 in the Petworth marble, which is derived from the same form- 

 ation. 



* See theplat«i accompanying the work of Sir H. Englefield on the Isle of Wight. 



