ZONE OF HARPOCERAS SERPENTINUM. 



121 



, r ■ ( Sandstone rock. 

 Inferior > c-u i j c j ^ 



p. .. -; Shales and Sandstones. 



(. Dogger Inf. Oolite. 



• V. 





Upper J Harp, bifrons. 

 Lias |_ Harp.falciferum. 



Middle J ^:/mfl^. spinatun. 

 Lias \ Amal. margaritatus. 



Fig. 6. — Saltwick from the South. 



Beleinnites and few fossils, about 18 feet thick, and resting upon (11) a dark, hard, 

 reddish, shale bed, changing into a ferruginous band, from 3 to G inches thick, and 

 underlain by (12) hard, dark shales, 12 feet thick, containing Belemnites subtenuis, and 

 Inoceramus dubius ; a band of remarkable, flattened spheroidal balls (13) separates the 

 above from the hard, dark shales of (14) the Serpentinum-zowe^ 20 feet thick, which 

 underlie the above. There are many fossils in this lower zone, as Harpoceras serpen- 

 tinum, Harp, exaratum. Harp, ovatum. Harp. Levisoni, Belemnites tubularis, hioceramus 

 dubius, and Extracrinus Philllpsii. Then (15) a band of pyritized, irregular balls, 

 covering 20 feet of hard grey shales (10). Beneath is another bed of dark shale (17), 

 with calcareous concretions and considerable portions of Jet ; this rock stands firm 

 against the sea, and is broken up by the workmen who mine it for Jet, which is here of 

 good quality, and used in manufacture. Below the Jet-rock are 20 feet of hard shales 

 with large nodules, which overlie 30 feet .of soft shales, containing Beleni. ctjlindricus. 



1 I have to thank Mr. William Smith, of Cheltenham, cousin and executor of the late Professor 

 Phillips, F.R.S., for his kind permission to use the above, and two other woodcuts, from the Professor's 

 last work on the 'Yorkshire Coast,' p. 14.5, 1875. 



16 



