FROM THE RED CHALK. 



163 



Section of Hunstanton Cliff. 



whole extent, and which under the influence of weathering impart to this portion of the 

 diff a jagged and rough appearance. Its characteristic fossils are spines of Cidaris vesi- 

 culosa, Holaster planus, Vermicularia umbonata, Tere- 

 bratulina gracilis, Terebratula semiglobosa, and Plica- 

 tula inflata. The band h, in thickness about 1 foot 2 

 inches, is conspicuous for a meandering and many- 

 branched Sponge {Syphonia paradoxica), specimens of 

 which are visible in the cliff only in short lengths, but 

 on the fallen blocks washed by the sea are seen to 

 extend continuously and horizontally over many square 

 feet of surface. The underside of b departs from the 

 general arrangement in the other courses ; for its base, 

 instead of forming a flat or approximately flat floor, is 

 broken up into a series of irregularly rounded ridges 

 and hollows, which undulate perpendicularly within the 

 limits of a few inches, and are represented in the section. 

 The fossils from this bed {b) are not so many (numeri- 

 cally speaking) as those in a. The chief forms are 

 8ipho)iia paradoxica, Terebrafida biplicata, Terebratula 

 semifflobosa,'^av. undata, Kingena lima, Avicula grgphmoides, 

 and Inoceramus latus. 



" Next in succession, in descending order, is the red 

 stratum, locally called the 'Red Chalk,' marked by an 

 abundance of organic remains, some of Avhich, as 

 Bourgiieficrinus rugosus and Terebratula cupillata, are, 

 in England, special to this deposit. Lithologically it 

 is unlike the beds above it, from the fact of its abound- 

 ing in great numbers of rolled and subangular pebbles 

 of quartz, slate, &c., which for the most part are of small 

 size and insignificant, though occasionally assuming 

 larger dimensions. In appearance it is divisible into 

 three almost equal portions, of which the first (a) has towards its base a large 

 quantity of fragments of Inocerami, the second and thickest division (b) is rich in 

 Belemnites, and the third and lowest (c) yields many Terebratulce. The bands a and b 

 are exceedingly hard and stony, and sufficiently tabular in character to have off'ered a 

 plane of resistance to former upheaving forces, and to have aff'orded great support to the 

 overlying white beds ; thus, although the whole cliff was evidently, in ancient geological 

 times, much disturbed, the perpendicular fissures which rise out of the yellow bands 



* A thickness of upwards of 30 feet is here omitted for convenience. 



