28 GEOLOGY or THE ISLE OF WIGHT. 



The bed with. Exogyra sinuata, vihich FiG. 12. 



comes to the shore under Atherfield ^ , 7 77 o 

 High Cliff, and forms a reef running Terchratula sella , bow 

 out through the beach about 350 yards 

 west of Whale Chine, is next in suc- 

 cession. It is about 10 feet thick, the 

 lower part consisting of brown and 

 reddish sand with spherical grains of 

 oolitic iron-ore, and containing Pinna 

 rohinaldina, D'Orb., while the upper 

 part forms the reef in which numerous 

 large Exogyra are conspicuous. 



Group v., or the Scaphites group of Fitton, has a thickness of 

 50 feet 4 inches, and may be divided into three beds, the lowest 

 of which is brown and rus(;-coloured sand about 20 feet thick, and 

 containing large Exogyra sinuata, Ostrea carinata, &c., and at 

 the bottom layers of Serpulce, Terehratulce, &c. Nodules in 

 layers containing Ancyloceras (Scaphites) gigas and A. Hillsii lie 

 next above this sand, and are succeeded in ascending order by 

 about 27 feet of dark-grey sandy clay, with the large Exogyra 

 sinuata, in the upper part. A reef contaiaing conspicuous clusters 

 of SerpulxB runs out from the cliif at this point. 



Group VI., or the Lower Crioceras beds, contains several ranges 

 of this fossil, imbedded in sand. The lowest range rises from 

 the beach on the west of Whale Chine ; the highest crosses 

 the bottom of the chine. The group is 16 feet 8 inches in 

 thickness. 



Group VII., the Walpen clay and sands, consists of a dark-green 

 mud at the bottom, about 27 feet thick, with nodules including 

 Exoqyra and Ammonites Martini, and of an upper division, clayey 

 above and sandy below, about 33 feet thick, containing Panopaa 

 {Myacites) mandihula. Pinna rohinaldina, and a Dentalium. The 

 clay-beds of this group form the undercliff, on to which Ladder 

 Chine opens. They rise from the beach about 200 yards east of 

 the chine, cross Whale Chine, and reach the top of the clJjfF 

 700 yards west of Whale Chine. Their position is always marked 

 by the springs they throw out, except close to the east side of 

 Whale Chine. 



Group VIII., the Upper Crioceras beds, is 46 feet 2 inches 

 thick, and contains four or more ranges of Crioceras Bowerbankii, 

 with Ammonites Martini, Germllia solenoides, Tcrebratula sella, 

 and Trigonia alcpformis ( T. vectiana, Lye). The top bed of the 

 group rises on the east of Walpen Chine, crosses Ladder Chine, 

 and may be seen in the chasm beneath it. The whole group 

 crosses Whale Chine also. 



Group IX., the Walpen and Ladder sands, consists of greenish 

 and grey sand, about 42 feet thick, with a layer of lenticular 

 masses of dark olive-green stone at the base, containing numerous 

 fossils. About 6 feet iiigher up is a thiu baud, consisting for the 

 greater ))art of ScrpulcB, apparently twisted together, associated 

 with Terebrutulu sella and other fossils. 



