﻿art. 
  21 
  CYCLOSTOMATOUS 
  BRYOZOA 
  CANU 
  AND 
  BASSLER 
  13 
  

  

  orbicular 
  or 
  elliptical. 
  The 
  peristomes 
  are 
  somewhat 
  salient, 
  thin, 
  

   scattered, 
  arranged 
  in 
  quincunx. 
  

  

  Measur 
  ements. 
  — 
  Diameter 
  of 
  orifices, 
  0.14 
  mm.; 
  diameter 
  of 
  peri- 
  

   stomes, 
  0.20 
  mm.; 
  diameter 
  of 
  branches, 
  0.75 
  mm. 
  

  

  Structure. 
  — 
  In 
  transverse 
  section 
  the 
  tubes 
  are 
  polygonal, 
  equal, 
  

   with 
  adjacent 
  and 
  very 
  thick 
  walls. 
  In 
  longitudinal 
  sections 
  the 
  

   tubes 
  are 
  cylindrical, 
  with 
  axial 
  gemmation. 
  The 
  thickening 
  of 
  the 
  

   walls 
  seems 
  to 
  correspond 
  to 
  the 
  salient 
  threads 
  of 
  the 
  exterior 
  sur- 
  

   face. 
  The 
  sectioned 
  specimen 
  was 
  very 
  small 
  and 
  did 
  not 
  permit 
  of 
  

   better 
  observations. 
  

  

  This 
  species 
  difFers 
  from 
  Clinopora 
  striatopora 
  Vine, 
  1885, 
  from 
  the 
  

   Albian 
  of 
  Cambridge, 
  England, 
  by 
  its 
  much 
  smaller 
  micrometric 
  

   measurements 
  and 
  very 
  different 
  arrangement 
  of 
  its 
  salient 
  threads. 
  

  

  Occurrence. 
  — 
  Lower 
  Cretaceous 
  (Aptian) 
  : 
  Faringdon, 
  England 
  

   (rare). 
  

  

  Cotypes.— 
  Cat. 
  No. 
  69852, 
  U.S.N.M. 
  

  

  Family 
  HETEROPORIDAE 
  Pergens 
  and 
  Meunier, 
  1886 
  

  

  Genus 
  HETEROPORA 
  Blainville, 
  1830 
  

  

  HETEROPORA 
  NUMMUL 
  ARIA, 
  new 
  species 
  

  

  Plate 
  20,, 
  figs. 
  6-8 
  

  

  Description. 
  — 
  The 
  zoarium 
  is 
  free, 
  discoid, 
  little 
  convex, 
  unilamel- 
  

   lar, 
  ornamented 
  with 
  feeble 
  tuberosities. 
  The 
  apertures 
  are 
  orbic- 
  

   ular, 
  arranged 
  in 
  quincunx, 
  placed 
  at 
  the 
  bottom 
  of 
  a 
  small 
  infundi- 
  

   buliform 
  cavity. 
  The 
  mesopores 
  are 
  small, 
  irregular, 
  polygonal, 
  widely 
  

   spaced. 
  

  

  Measurements. 
  — 
  Diameter 
  of 
  aperture, 
  0.08 
  mm.; 
  diameter 
  of 
  

   mesopores, 
  0.04 
  mm. 
  

  

  Occurrence. 
  — 
  Lower 
  Cretaceous 
  (Aptian) 
  : 
  Faringdon, 
  England. 
  

  

  Holotype.— 
  -Cat. 
  No. 
  69853, 
  U.S.N.M. 
  

  

  Genus 
  MULTICRESCIS 
  D'Orbigny, 
  1852 
  

  

  MULTICRESCIS 
  TUBEROSA 
  Roemer, 
  1839 
  

  

  1909. 
  Multicrescis 
  tuberosa 
  Gregory, 
  Catalogue 
  of 
  the 
  Cretaceous 
  Bryozoa 
  in 
  the 
  

   British 
  Museum, 
  vol. 
  2, 
  p. 
  205, 
  figs. 
  52-54, 
  pi. 
  9, 
  fig. 
  4. 
  (Bibliography 
  

   and 
  geological 
  distribution.) 
  

  

  Our 
  specimen 
  corresponds 
  exactly 
  to 
  Gregory's 
  figure, 
  so 
  that 
  a 
  

   new 
  figure 
  is 
  unnecessary. 
  Canu, 
  in 
  1902, 
  has 
  noted 
  the 
  occurrence 
  

   of 
  this 
  species 
  at 
  Sainte-Croix. 
  

  

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

   Switzerland. 
  

  

  