﻿164 
  Scientific 
  Intelligence. 
  

  

  very 
  broad 
  faces, 
  the 
  hinder 
  being 
  slightly 
  convex, 
  while 
  the 
  

   eighth 
  like 
  the 
  fifth 
  and 
  sixth 
  is 
  coelocyrtean, 
  but 
  differs 
  from 
  

   the 
  others 
  in 
  the 
  expansion 
  of 
  its 
  neural 
  spine 
  and 
  the 
  arching 
  

   backward 
  of 
  its 
  postzygapophyses 
  over 
  the 
  convex 
  prezygapoph- 
  

   yses 
  of 
  the 
  first 
  dorsal 
  upon 
  which 
  the 
  former 
  play 
  backward 
  

   and 
  forward. 
  (Cf. 
  Huxley's 
  Anatomy 
  of 
  Vertebrated 
  Animals, 
  

   London, 
  1871, 
  p. 
  171.) 
  

  

  2. 
  Cycadean 
  Monmcism 
  ; 
  by 
  G. 
  R. 
  Wi 
  eland 
  (communicated). 
  

   — 
  The 
  living 
  and 
  fossil 
  Cycads, 
  so 
  far 
  as 
  hitherto 
  observed, 
  are 
  

   dioecious. 
  Hence, 
  it 
  is 
  important 
  to 
  note 
  that 
  certain 
  Mesozoic 
  

   species 
  from 
  the 
  Black 
  Hills, 
  now 
  in 
  the 
  Yale 
  Museum, 
  and 
  

   referred 
  to 
  the 
  genus 
  Cycadeoidea 
  as 
  commonly 
  emplo3^ed, 
  have 
  

   been 
  recently 
  found 
  to 
  be 
  monoecious. 
  These 
  possess 
  essentially 
  

   the 
  types 
  of 
  male 
  and 
  female 
  fructification 
  described 
  by 
  the 
  writer 
  

   in 
  his 
  preliminary 
  papers 
  on 
  a 
  Study 
  of 
  American 
  Fossil 
  Cycads, 
  

   Parts 
  I-HI 
  (this 
  Journal, 
  March-May, 
  1899). 
  

  

  The 
  species 
  there 
  recorded 
  as 
  dioecious 
  are 
  probably 
  of 
  that 
  

   nature. 
  All 
  the 
  evidence 
  at 
  present 
  available 
  strongly 
  points 
  

   to 
  the 
  dioecism 
  of 
  Cycadeoidea 
  Colei, 
  C. 
  turrita^ 
  C. 
  Wielandi, 
  

   C. 
  ingens^ 
  etc. 
  On 
  the 
  contrary, 
  other 
  species 
  in 
  full 
  fruit 
  

   recently 
  studied 
  bear 
  typical 
  male 
  and 
  female 
  fructifications 
  on 
  

   the 
  same 
  trunk. 
  Of 
  these 
  may 
  be 
  mentioned 
  Cycadeoidea 
  Minne- 
  

   kahtensis, 
  C. 
  Wellsi, 
  C. 
  Dacotensis^ 
  etc. 
  The 
  limits 
  of 
  this 
  monoe- 
  

   cism 
  and 
  dioecism 
  can 
  not 
  be 
  determined 
  without 
  abundant 
  

   material 
  and 
  a 
  long 
  series 
  of 
  observations. 
  Fortunately, 
  the 
  

   richness 
  of 
  the 
  Yale 
  collection 
  will 
  go 
  far 
  towards 
  solving 
  this 
  

   problem. 
  

  

  The 
  condition 
  of 
  monoecism 
  in 
  Cycads 
  thus 
  places 
  this 
  group 
  

   of 
  plants 
  one 
  step 
  nearer 
  the 
  conifers. 
  Nevertheless, 
  in 
  view 
  of 
  

   the 
  fact 
  that 
  the 
  Cycads 
  of 
  the 
  Black 
  Hills 
  Jurassic 
  were 
  so 
  pro- 
  

   liferous 
  in 
  habit, 
  it 
  is 
  not 
  surprising 
  that 
  monoecious 
  forms 
  should 
  

   occur, 
  especially 
  when 
  the 
  o^reat 
  variability 
  of 
  gymnosperms 
  in 
  

   this 
  respect 
  is 
  considered. 
  That 
  these 
  Mesozoic 
  species, 
  so 
  closely 
  

   related 
  as 
  to 
  have 
  been 
  included 
  in 
  a 
  single 
  genus, 
  should 
  be 
  

   found 
  to 
  possess 
  both 
  kinds 
  of 
  unisexuality, 
  however, 
  adds 
  great 
  

   interest 
  to 
  the 
  Gycadece, 
  as 
  well 
  as 
  an 
  important 
  chapter 
  to 
  the 
  

   knowledge 
  of 
  sexual 
  characters 
  in 
  plants. 
  

  

  3. 
  Su7' 
  Stereosternumturnidtim, 
  Cope 
  ^ 
  by 
  H. 
  B. 
  Geixitz. 
  Ann. 
  

   Soc. 
  geol. 
  de 
  Belg., 
  xxv, 
  8 
  pages, 
  and 
  one 
  large 
  double-page 
  plate, 
  

   1899. 
  — 
  Dr. 
  Geinitz 
  reproduces, 
  by 
  some 
  photographic 
  process, 
  the 
  

   forms 
  of 
  two 
  fine 
  specimens 
  of 
  this 
  species 
  obtained 
  from 
  the 
  

   ?Permian 
  beds 
  of 
  Sfio 
  Paulo 
  (Brazil), 
  and 
  now 
  in 
  the 
  Royal 
  

   Museum 
  of 
  Mineralogy 
  at 
  Dresden. 
  In 
  the 
  text, 
  the 
  formations 
  

   and 
  known 
  fossil 
  associates, 
  as 
  well 
  as 
  the 
  biological 
  characters 
  of 
  

   the 
  specimens, 
  are 
  defined. 
  Though 
  believed 
  to 
  be 
  Permian, 
  the 
  

   exact 
  age 
  of 
  the 
  beds 
  is 
  not 
  established 
  beyond 
  controversy. 
  

  

  