134  PROCEEDINGS  OF  THE  GEOLOGICAL  SOCIETY.  [May  1 893, 
He  divides  the  Rhgetics  into  two  groups,  viz.  the  Avicula  contorta- 
shaies  and  the  Upper  Rhaetic  Series.  The  base  of  the  Avicula- beds 
is  characterized  by  black  shales  with  a  very  thin  seam  and  small 
pockets  of  pyritic  grit,  containing  fish-teeth,  scales,  and  fin-spines, 
coprolites,  and  pebbles  of  white  quartz  ;  there  is  no  true  4  Bone-bed 9 
as  at  Aust  Cliff.  The  contrast  between  this  fossiliferous  horizon 
with  its  Rhaetic  fish-fauna  and  the  so-called  4  Tea-green  Marls/ 
containing  nothing  but  indeterminable  plant-remains,  must  be  very 
strong.  Indeed,  unless  there  is  evidence  of  a  very  different  character 
forthcoming  elsewhere,  one  cannot  help  expressing  surprise  that 
anyone  should  ever  have  thought  of  uniting  them.  The  most 
natural  supposition  seems  to  be  that  the  4  Tea-green  Marls  ’  are 
merely  the  upward  continuation  of  the  Red  Marls,  where  the  iron- 
oxides  have  undergone  slight  reduction  in  consequence  of  the 
amount  of  carbonaceous  matter  which  they  contain. 
His  Upper  Rhaetic  Series,  consisting  of  limestone  and  shales,  is 
terminated  upwards  by  a  band  of  compact,  light  blue,  concretionary 
limestone  with  conchoidal  fracture  and  dendritic  markings,  which  he 
takes  to  be  the  equivalent  of  the 4  Gotham  Marble.’  This  series, 
besides  certain  characteristic  Rhaetic  fossils,  yields  abundance  of 
the  little  freshwater  plant,  Naiadita ,  associated  with  numerous 
Ostracoda.  These  beds  he  regards  as  homotaxial  with  the  shales 
and  nodular  limestones,  containing  Estheria,  of  the  Midlands,  which 
directly  overlie  the  Avicula  contorta- shales  in  that  region. 
Triassic  and  Permian  Geology. 
These  two  systems  are  so  intimately  connected  in  this  country 
that,  although  the  one  is  regarded  as  Mesozoic  and  the  other  as 
Palaeozoic,  they  must  perforce  be  taken  together.  There  are  indeed 
geologists  who  seem  disposed  to  look  upon  certain  developments  of 
the  Permian  as  simply  the  base  of  the  Trias,  and,  as  we  shall 
perceive  in  the  sequel,  there  have  been  wide  differences  of 
opinion  as  to  whether  certain  rocks  are  to  be  regarded  as  Permian 
or  Triassic.  The  total  dissimilarity  which  prevails  between  the 
Permians  north  of  Nottingham  (east  of  the  Pennine  Chain)  and 
those  to  the  south-west  of  that  town  adds  to  the  difficulty.  The 
papers  read  before  the  Society  relate  (1)  to  the  South-west  of 
England  ;  (2)  to  the  Midlands  ;  (3)  to  the  Estuary  of  the  Tees. 
The  South-west  of  England. — As  regards  the  first  district,  Mr. 
Worth  submitted  evidence  of  the  possibility  of  the  existence  of  a 
submarine  Triassic  outlier  off  the  Lizard,  thus  carrying  the  English 
