Y  ol.  49.]  ANNIVERSARY  ADDRESS  OF  THE  PRESIDENT.  II9 
we  find  in  the  central,  and  to  a  certain  extent  in  the  upper 
portions,  great  numbers  of  the  section  Simbirslcites  of  the  genus 
Olcostephanus ,  of  which  01.  ( SimbirsJcites )  speetonensis ,  Young  and 
Bird,  may  be  regarded  as  the  most  characteristic.  The  lower  part 
of  the  zone,  on  the  other  hand,  is  occupied  by  representatives  of  the 
genus  Hoplites ,  better  known  to  English  readers  under  the  collective 
title  of  Am.  regalis  ( noricus ).  In  this  portion  of  the  Speeton  section, 
therefore,  Am.  speetonensis  characterizes  the  upper  sub-zone  and 
Am.  regalis  the  lower  sub-zone,  the  Tealby  Clay  being  correlated 
with  the  former  and  a  portion  of  the  ferruginous  rocks  of  Claxby 
with  the  latter.  In  the  clays  of  this  zone  at  Speeton  it  is  noticeable 
that  many  species  appear  and  disappear ;  but  still  it  is  principally 
throughout  this  horizon  that  a  Neocomian  fauna  is  encountered. 
This  zone  of  Bel.  jaeulum  seems  to  be  partially  represented  at  two 
localities  in  Central  Bussia. 
The  fourth  zone  is  one  about  whose  precise  age  and  relations  there 
seems  to  have  been  considerable  difference  of  opinion.  At  Speeton 
this  zone  consists  of  about  35  feet  of  clays  lying  between  two  thin 
nodular  bands,  the  upper  of  which  is  called  the  4  Compound  Modular 
Band,’  whilst  the  lower  is  known  as  the  ‘  Coprolite-bed.’  This  is 
the  zone  characterized  by  Belemnites  lateralis,  a  group  which  is 
held  to  include  five  species,  viz.  B.  lateralis ,  Phil.,  B.  subquaclratus , 
Bom.,  B.  russiensis,  D'Orb.,  B.  explanatus ,  Phil.,  and  B.  explana- 
toicles,  Pavl.  In  the  4  Compound  Nodular  Band  ’  there  are  still  con¬ 
siderable  traces  of  the  fauna  of  the  third  zone,  such  as  Hoplites 
regalis  {noricus),  Grioceras,  etc.,  so  much  so  that  it  must  be  regarded 
to  some  extent  as  a  kind  of  blend  of  the  two  zones,  such  as  is  found 
to  be  the  case  with  so  many  bands  in  which  rolled  and  transported 
nodules  occur.  The  Ammonites  of  this  fourth  zone  are  frequently 
of  great  size  and  belong  to  the  section  Polyptychites  of  the  genus 
Olcostephanus ,  regarding  which  Prof.  Pavlow  writes  that  representa¬ 
tives  of  this  group  are  most  varied  and  most  numerous  in  Northern 
Bussia  (the  region  of  the  Petchora),  in  Eastern  Bussia  (government 
of  Simbirsk),  in  Yorkshire,  and  in  Northern  Germany.  Amongst 
these  forms  are  the  Ammonites  referred  by  Mr.  Leckenby  to  the 
Coronati ,  and  regarded  by  him  as  Portlandian,  about  whose  actual 
position  in  the  Speeton  section  there  has  existed  a  certain  amount 
of  doubt. 
Mr.  Lamplugh  admits  that  the  fauna  accompanying  Bel.  lateralis, 
both  at  Speeton  and  in  Lincolnshire,  is  peculiar.  It  includes  forms 
very  near  to  those  which  attain  their  complete  development  in  the 
