﻿18 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL. 
  MUSEUM 
  vol.67 
  

  

  hollow; 
  many 
  lamellae 
  curve 
  about 
  a 
  solid 
  branch, 
  as 
  in 
  Leiosoecia 
  

   proximo,. 
  

  

  In 
  longitudinal 
  section 
  the 
  tubes 
  are 
  cylindrical, 
  with 
  dorsal 
  gem- 
  

   mation 
  on 
  a 
  basal 
  lamella; 
  they 
  are 
  much 
  recurved 
  at 
  their 
  extrem- 
  

   ity. 
  The 
  mesopores 
  are 
  long, 
  numerous, 
  variable 
  in 
  diameter 
  and 
  

   length. 
  The 
  exterior 
  lamella 
  has 
  its 
  origin 
  in 
  a 
  tube 
  of 
  an 
  internal 
  

   lamella; 
  the 
  tubes 
  and 
  the 
  mesopores 
  are 
  very 
  much 
  shorter, 
  but 
  

   they 
  have 
  the 
  same 
  characters 
  as 
  the 
  tubes 
  of 
  the 
  internal 
  lamella. 
  

  

  In 
  transverse 
  section 
  the 
  tubes 
  are 
  polygonal, 
  with 
  thin 
  and 
  adja- 
  

   cent 
  walls. 
  They 
  are 
  much 
  smaller 
  in 
  the 
  vicinity 
  of 
  the 
  basal 
  

   lamella, 
  which 
  proves 
  that 
  these 
  tubes 
  are 
  club-shaped 
  in 
  their 
  infe- 
  

   rior 
  part 
  and 
  cylindrical 
  as 
  soon 
  as 
  they 
  are 
  recurved. 
  

  

  Affinities. 
  — 
  This 
  species 
  much 
  resembles 
  Acanthopora 
  pulcliella 
  De 
  

   Loriol, 
  1868. 
  According 
  to 
  the 
  figures 
  of 
  this 
  author, 
  the 
  zoarial 
  sur- 
  

   face 
  presents 
  small 
  very 
  regular 
  tuberosities 
  surrounded 
  by 
  radiating 
  

   mesopores. 
  We 
  have 
  not 
  had 
  occasion 
  to 
  observe 
  the 
  genotype 
  and 
  

   we 
  understand 
  little 
  of 
  this 
  particular 
  arrangement. 
  We 
  believe 
  

   that 
  this 
  is 
  a 
  figure 
  somewhat 
  fanciful 
  of 
  a 
  Multicrescis, 
  with 
  tube- 
  

   rose 
  visors, 
  like 
  the 
  present 
  species. 
  However, 
  as 
  we 
  are 
  not 
  able 
  to 
  

   prove 
  this 
  supposition, 
  we 
  will 
  maintain 
  the 
  generic 
  term 
  Multicrescis. 
  

   If 
  by 
  chance 
  it 
  is 
  identical 
  with 
  De 
  Loriol's 
  species 
  the 
  name 
  of 
  the 
  

   genus 
  would 
  only 
  be 
  changed 
  and 
  all 
  Multicrescis 
  with 
  visors 
  would 
  

   then 
  be 
  Acanthopora. 
  

  

  It 
  is 
  to 
  be 
  noted 
  that 
  the 
  exterior 
  lamella 
  appears 
  to 
  have 
  only 
  a 
  

   single 
  origin. 
  In 
  the 
  other 
  known 
  Multicrescis 
  there 
  are 
  alway 
  several 
  

   points 
  of 
  origin. 
  

  

  Occurrence. 
  — 
  Lower 
  Cretaceous 
  (Valangian) 
  : 
  Sainte-Croix 
  (Vaud) 
  , 
  

   Switzerland 
  (common). 
  

  

  Cotypes. 
  — 
  Cat. 
  No. 
  69859, 
  U.S.N.M., 
  and 
  Museum 
  Comparative 
  

   Zoology. 
  

  

  MULTICRESCIS 
  (ACANTHOPORA) 
  FORMOSA, 
  new 
  species 
  

  

  Plate 
  21, 
  figs. 
  10-12 
  

  

  Affinities. 
  — 
  Only 
  the 
  figured 
  specimen 
  has 
  been 
  found, 
  and 
  a 
  

   description 
  is 
  not 
  given, 
  for 
  we 
  have 
  not 
  been 
  able 
  to 
  make 
  thin 
  sec- 
  

   tions, 
  and 
  on 
  the 
  surface 
  we 
  can 
  not 
  see 
  the 
  difference 
  between 
  the 
  

   orifice 
  of 
  the 
  tubes 
  and 
  those 
  of 
  the 
  mesopores. 
  

  

  This 
  species 
  has 
  an 
  aspect 
  very 
  close 
  to 
  Acanthopora 
  pulchella 
  De 
  

   Loriol, 
  1868, 
  but 
  the 
  zoarial 
  tuberosities 
  are 
  here 
  triangular 
  visors 
  

   diversely 
  oriented, 
  so 
  that 
  it 
  is 
  difficult 
  to 
  discover 
  the 
  pores 
  to 
  which 
  

   they 
  correspond. 
  

  

  The 
  genus 
  Acanthopora 
  D'Orbigny, 
  1840, 
  differs 
  from 
  Neuropora 
  

   in 
  that 
  the 
  thickened 
  borders 
  of 
  the 
  peristomes 
  present 
  small 
  conical 
  

   points 
  in 
  place 
  of 
  the 
  elongated 
  veinules 
  (Haime, 
  1854). 
  The 
  figures 
  

   given 
  by 
  Haime 
  and 
  by 
  De 
  Loriol, 
  1868, 
  indicate 
  clearly 
  that 
  the 
  

  

  