﻿ANNIVERSARY 
  ADDRESS 
  OF 
  THE 
  PRESIDENT. 
  235 
  

  

  the 
  Kellaway, 
  Oxford, 
  Corallian, 
  Kimmeridgian, 
  and 
  Portlandian 
  

   stages/' 
  

  

  Genus 
  Scaphites, 
  Park. 
  — 
  This 
  genus, 
  like 
  Ancyloceras, 
  needs 
  

   little 
  notice 
  here. 
  All 
  the 
  species 
  are 
  Cretaceous. 
  

  

  Genus 
  Hoplites 
  > 
  Neum. 
  — 
  The 
  highly 
  ornamented 
  shells 
  of 
  this 
  

   genus 
  form 
  conspicuous 
  groups 
  in 
  the 
  Cretaceous 
  rocks, 
  of 
  which 
  

   they 
  are 
  characteristic. 
  The 
  old 
  groups 
  Tuberculati 
  and 
  Dentati 
  

   partly 
  fall 
  into 
  the 
  genus 
  Hoplites. 
  The 
  " 
  Dentati 
  interrupt! 
  " 
  

   would 
  receive 
  certain 
  forms 
  of 
  Hop. 
  interruptus 
  and 
  Hop. 
  splendens, 
  

   Hop. 
  falcatus 
  being 
  one 
  of 
  the 
  known 
  "Tuberculati." 
  The 
  Gault, 
  

   Upper 
  Greensand, 
  and 
  Lower 
  Chalk 
  contain 
  the 
  genus 
  Hoplites. 
  

  

  Genus 
  Acanthoceras, 
  JSTeumayer. 
  — 
  Neumayer 
  instituted 
  this 
  new 
  

   group 
  to 
  receive 
  certain 
  species 
  once 
  included 
  in 
  the 
  genus 
  Hoplites. 
  

   In 
  the 
  old 
  classification 
  many 
  were 
  placed 
  byD'Orbigny 
  in 
  his 
  group 
  

   vii. 
  (Rhotomagenses), 
  and 
  by 
  Pictet 
  in 
  group 
  ix. 
  {Dentati, 
  Yon 
  Buch). 
  

   The 
  siphonal 
  area 
  varies 
  considerably 
  ; 
  in 
  some 
  the 
  median 
  line 
  is 
  

   channelled 
  and 
  with 
  rows 
  of 
  tubercles 
  on 
  the 
  border, 
  thus 
  inter- 
  

   rupting 
  the 
  ribs 
  from 
  crossing 
  the 
  ventral 
  margin, 
  or 
  the 
  tubercles 
  

   are 
  arranged 
  in 
  rows, 
  or 
  pass 
  along 
  the 
  median 
  line 
  in 
  a 
  kind 
  of 
  

   knotted 
  keel. 
  This 
  short 
  diagnosis 
  will 
  suggest 
  A. 
  mammillare, 
  A. 
  

   rhotomagense, 
  A. 
  sussexense, 
  and 
  A. 
  Mantelli 
  under 
  the 
  old 
  classifi- 
  

   cation, 
  groups 
  vii. 
  and 
  ix. 
  All 
  the 
  species 
  are 
  Cretaceous. 
  

  

  Acanthoceras 
  Mantelli. 
  "^ 
  

  

  rhotomagense. 
  

  

  sussexense. 
  )■ 
  British 
  species. 
  

  

  Woolgari. 
  

  

  mammillare. 
  ) 
  

  

  Brottianum. 
  1 
  

  

  Deverianum. 
  I 
  French 
  species. 
  

  

  Martinsii. 
  J 
  

  

  Genus 
  Stoliczkaia. 
  — 
  All 
  are 
  Indian 
  species 
  in 
  this 
  genus. 
  Neu- 
  

   mayer 
  established 
  this 
  group 
  to 
  receive 
  some 
  remarkable 
  Ammonites 
  

   figured 
  in 
  Stoliczka's 
  great 
  work 
  " 
  On 
  the 
  Ammonitidce 
  of 
  the 
  Chalk 
  

   Rocks 
  of 
  Southern 
  India 
  " 
  [vide 
  this 
  work 
  for 
  the 
  types 
  of 
  the 
  

   genus] 
  . 
  

  

  The 
  genera 
  Crioceras, 
  Leveille, 
  Toococeras, 
  D'Orb., 
  and 
  Heteroceras, 
  

   D'Orb., 
  need 
  only 
  be 
  mentioned 
  ; 
  they 
  have 
  no 
  special 
  value 
  in 
  the 
  

   modern 
  nomenclature 
  of 
  the 
  Ammonitidae. 
  

  

  Genus 
  Aspidoceras, 
  Zittel. 
  — 
  Yon 
  Buch's 
  group 
  xiii. 
  {Armati) 
  

   embraces 
  the 
  species 
  of 
  Aspidoceras. 
  The 
  chief 
  species 
  are 
  Asp. 
  

   longispinum, 
  from 
  the 
  Kimmeridge 
  and 
  Oxford 
  Clays, 
  Asp. 
  per- 
  

   armatum, 
  Oxfordian 
  and 
  Corallian 
  : 
  this 
  last 
  species 
  is 
  the 
  type 
  of 
  a 
  

   large 
  section. 
  D'Orbigny's 
  type 
  for 
  the 
  Per 
  armati 
  is 
  Asp. 
  altenense, 
  

   a 
  Corallian 
  form. 
  

  

  Genus 
  Peltoceras, 
  Waagen. 
  — 
  In 
  England 
  the 
  genus 
  Peltoceras 
  is 
  

   confined 
  to 
  the 
  Oxfordian 
  stage, 
  and 
  only 
  2 
  species 
  represent 
  it 
  — 
  

   P. 
  athleta, 
  Phill., 
  and 
  P. 
  Williamson^ 
  PhilL 
  

  

  Genus 
  Simoceras, 
  Zitt. 
  — 
  Reinecke's 
  species, 
  S. 
  anceps, 
  is 
  a 
  British 
  

   species 
  ranging 
  through 
  the 
  Oxfordian 
  stage 
  ; 
  it 
  is 
  possibly 
  the 
  Am. 
  

  

  