Part 4

The latter of which agrees remarkably well with the colour of the specimen, for the Red Chalk of Hunstanton is brighter than that of Speeton.

Two specimens of the borings of Kentish Town, one a red argillaceous and the other a siliceous mass, gave the following results:--

Argillaceous--

Peroxide of iron 6.5 Carbonate of lime 13.5 Silica and alumina (chiefly the latter) 80.0 ----- 100. -----

Siliceous--

Peroxide of iron 2.5 Carbonate of lime 23.5 Silica, with a little alumina 74.0 ----- 100. -----

Whether any connexion can be traced between these last two and the two former, I leave for others to decide.

The following list of books may perhaps be useful to those who wish to further investigate the subject:--In

Professor Phillips' Geology of Yorkshire,

Young and Bird's Survey of the Yorkshire Coast,

Dr. Fitton's Memoir of the Strata below the Chalk,

Taylor's Hunstanton Cliff (Phil. Mag. vol. lxi.),

Woodward's Geology of Norfolk,

Rose on the Geology of West Norfolk (Phil. Mag. for the years 1835 and 1836),

will be found some account of the English Red Chalk. And in

Sedgwick and Murchison on the Structure of the Eastern Alps (Geol. Soc. Trans. vol. iii. Second Series),

Sir. R. I. Murchison on the Geological Structure of the Alps (Quart. Geol. Journal, vol. v.),

Prof. T. A. Catullo on the Epiolitic Rocks of the Venetian Alps (Quart. Geol. Journal, vol. vii),

Count A. de Zigno on the Stratified Formations of the Venetian Alps (Quart. Journal Geol. Soc. vol. vi.),

will be seen an outline of the Scaglia or Red Chalk of Italy.

By the kindness of Dr. Bowerbank, Messrs. Wetherell, Bean, Leckenby, and Rose, in permitting me to see the specimens in their respective cabinets, and to whom, as well as to Mr. Rupert Jones, I must express great obligations for much valuable information, the accompanying list of the Red Chalk fossils of Speeton, Hunstanton, and Muswell Hill has been compiled. To the Council of the Geological Society, I am also indebted for permission to figure from the Society's Museum the Inoceramus Crispii, on pl. i. fig. 4.

LIST OF FOSSILS FROM THE RED CHALK.

Key to Table Columns:

S: Speeton H: Hunstanton MH: Muswell Hill

S H MH Cristellaria rotulata, D'Orb. Pl. II. fig. 8 × Sowerby's Min. Conchology, tab. 121, page 45. (In the collection of Mr. Jones.)

Siphonia pyriformis. Pl. II. fig. 2 × Goldfuss Petrifacta, tab. 6, fig. 7, page 16. (In the collection of Mr. Rose.) This is probably the head of the next.

Spongia paradoxica. Pl. II. fig. 1 × Geol. Trans. 2, tab. 27, fig. 1, page 377. (In the collections of Mr. Rose and Author.)

Bourgueticrinus rugosus. Pl. III. fig. 5 × D'Orbigny's Hist. des Crinoides, tab. 17, fig. 16-19. (In the collections of Mr. Rose and Author.)