DAVIS ! SECTIONS IN THE LIASSIC AND OOLITIC ROCKS OF YORKSHIRE. 177 
Soft shales with a suc- 
cession of sandy and 
marly bands. 140ft. 
Shales with hard sandy bands, the 
upper parts covered by fucoidal 
markings. 
(Zone of Am. oxynotus) Gryphcea 
A. Soft shales with a sue- incurva, Ammonites abundant. 
Shales with marly calcareous bands, 
generally very shelly. 
(Zone of Am. Bucklandi) Gryphcea 
incurva, Hippopodium ponderosum 
in bands, Am. semicostatus. 
The zone of Ammonites Bucklandi (a) forms a series of outer scars in 
the Bay parallel with the coast line, and dipping at an angle of 4° to 
the S.S.W. The outcrop is about 300 yards in extent, and the rock 
consists of soft grey shales with harder calcareous sandstones inter- 
spersed. They are only exposed at low spring tides, and are rendered 
difficult to investigate by the quantities of seaweeds which is attached 
to the beds. It is only after the hot summer weather has to some 
extent destroyed the weed that they can be examined satisfactorily. 
The following is a list of the principal fossils found in these 
beds : — 
Gryphsea arcuata, Lam. 
Lima Hettangiensis, Terg. 
Monotis inaequivalvis, Sow. 
Pecten calvus, Goldf. 
„ Thiollierei, Dumort. 
,, textorius, Schloth. 
Perna infraliassica, Quenst. 
Cardinia hybrida, Stutch. 
Protocardium oxynoti, Quenst. 
Hippopodium ponderosum, Sow. 
Leda galathea, D'orb. 
,, Renevieri, Opp. 
Lucina limbata, T. & B 
Modiola lsevis, Sow. 
Nucula navis, Piette 
Pholadomya glabra, Ag. 
Chemnitzia trivia, Tate. 
Cerithium sp. 
Dentalium etalense, Terg. & P. 
Ammonites Bucklandi, Sow. 
,, semicostatus, Y. & B. 
,, Turneri, Sow. 
Belemnites acutus, Miller. 
Pentacrinus tuberculatum 
The Ammonites Oxynotus Zone (b) is about 110 feet in thickness, 
it consists of alternating layers of soft shale and bands of sandy 
marl, the latter being remarkable for impressions of fucoids which are 
rendered visible by exposure to sea-water. Fossil ammonites are 
