542 R. F. Tomes — Some Cretaceous Madi'eporarla. 



A section of the G-ault at Folkestone is given, not from any new- 

 features it contains, but to afford the opportunity of pointin;^ out 

 the exact stratigraphical position of the several species of Madre- 

 jporaria there met with. 



Section of the Gault at Folkestone. 

 ft. in. 



1. Eubbly yellow Gault about 39 | Pecten, Jstrea, Samites, Am- 



\ monites Goodhalli. 



2. Light-coloiu-ed mottled Gault,with"] 



layers of phosphate nodules about I , . . , . , , -n , ■ 



4.-U ■ iji J T, J I oo n ( Ammonites cristatus, Pentacrinus 



the imddle, and a hard seam near )>22 ■ pv, • 

 the bottom, with a layer of No- j ^ J^ittom. 



dules beneath it j 



o T -u J VI n li. -ii \ ( Casts of Inoceramus above the hard 



3. Inoceramus bed, blue Gault, with Inn) mi ji rrr-y^ ? ■ ■ 



11 . Vi -iji J 9 < seava—lrochocyathus Wiltshirti, 



a hard seam m the middle I ) ^ ? /;• i i ; • 



( Caryophylha Boweroanki. 



d-TSTrllKrl ^ f\ \ TrocJwcyathus Harveyamis, and a 

 ( variety, Bathycyathus Soiveibyi. 



5. Very dark Gault with a hard seam ) 7 « 

 at the bottom ] 



6. Dark mottled bed 3 



iFucoids, Nautilus, Gervillea, Cera- 

 iotrochus insignis, Siiiilotroclms 

 cylindricus, S. calcaratus, Lepto- 

 cyathiis gracilis. 



8. Light fawn-coloured bed 7 Crustacea, Pinna. 



9. Very dark Gault 5 Mytilus,Trochocyathusnarveyanus. 



10. Gault 5 Cyclocyathus Fittoni. 



11. Gault, containing bands of no- "> „ „ 

 dules of sulphate of iron | 



12. Dark-coloured Lower Greensand, said to contain corals. 



The foregoing section was copied by me from one in the possession 

 of the well-known collector of Gault fossils, Mr. J, Griffiths, of 

 Folkestone, whose practical knowledge of the locality is very intimate. 

 This was taken to the spot, and made use of in fixing the position 

 of the corals. It has subsequently been correlated with the one 

 published by Mr. Price in the Quarterly Journal of the Geological 

 Society.^ 1 regret that I did not consult Mr. Price's section before 

 visiting the coral-bearing strata at Folkestone, as I should have 

 referred to it instead of the one I have here introduced. A great 

 many of the species were observed in situ, and were placed in the 

 section on the spot. Nearly all the corals I saw were in a thin seam 

 between beds number 7 and 8. The common species, Cydocijathis 

 Fittoni, is not, however, by any means confined to the one bed 

 mentioned, but has a vertical range of nearly fifty feet. Probably 

 also Trochocyaihus Harveyamis has a somewhat similar range. 



Ceeatotkochus insignis. Dune, sp. PI. XIV. Fig. 6. 

 Smilotrochus insignis. Dune. Supp. Brit. Foss. Cor. pt. ii. p. 37, pi. xvi. fig. 18, 1870. 

 Having been struck with the very great resemblance between the 

 Smilotrochus insignis of Duncan and the CeratoirocJms ornatus of 

 M. de Fromentel, I broke up some specimens of the former, from 

 the Gault of Folkestone, and ascertained at once, by the existence of 

 1 Quart. Journ. Geol. Soc. 1874, vol. xxx. p. 342. 



