226 GEOLOGY OF THE ISLE OF WIGHT. 



do not occur in any other strata. The Gervillia anceps 

 (PL IV. fig. 3) is crowded together in groups of hun- 

 dreds, and the shells are as perfect as if lying in their 

 native bed. Several small shells from the Cracker's rock 

 are figured in PI. V. (figs 4, 6, 7, 8, 9, 10). These 

 fossils occur in such numbers and variety, that almost 

 every considerable fragment of the rock will be found to 

 contain several species. 



5. Upper Lobster clay.— A deposit of saponaceous clay, 

 similar to No. 3 ; and abounding in the same kind of fos- 

 sil lobsters as that bed. It also contains ammonites and 

 other shells : total thickness 20 feet. 



6. Zone of Terebratulce. — Clays full of fossils, 20 feet : 

 above which is a bed of dark sand, 22 feet in thickness, 

 enclosing immense numbers of Terebratulm (PI. V. 

 fig. 5), and Serpulai. 



7. Zones of Gryphem and Scaphites. — A series of sands and 

 clays, including layers of QrypJiecR (the large bivalve figured 

 in PI. V. fig. 3), imbedded in dark sand, and alternating 

 with bands of nodules which contain gigantic Scaphites 

 (PI. V. fig. 1\), ammonites, and numerous other fossils : 

 total thickness 155 feet. 



S. Upper zone of Terebratodce. — A bed of sand 30 feet 

 thick, full of layers of Tercbratulae (chiefly of Terebratula 

 biplicata) : above which is a stratum of dark sand, 24 

 feet thick, with a band of Grypheae as in No. 7, but with- 

 out the Scaphite nodules. 



9. Ferruginous sands. — Sands highly ferruginous, with layers 

 of dark blue clay, and bands of ironstone nodules full of 

 casts of shells (PI. IV. fig. 7, PI. V. fig. 1), of the genera 

 Venus, Thetis, Trigonia, &c. Seams of lignite are dis- 

 seminated through the lower beds in undulated laminae ; 

 and thin layers of ironstone grit without fossils, occur in 

 the upper part of the series. The beds in contact with 

 the Gait are generally of this character. 



