﻿CYCLOSTOMATOUS 
  BRYOZOA 
  CANU 
  AND 
  BASSLER 
  

  

  91 
  

  

  fied 
  and 
  could 
  not 
  be 
  sectioned, 
  but 
  a 
  well-preserved 
  example 
  from 
  

   Berklingen 
  has 
  afforded 
  some 
  interesting 
  results. 
  In 
  the 
  transverse 
  

   section 
  here 
  figured 
  the 
  tubes 
  are 
  polygonal, 
  with 
  a 
  rounded 
  center, 
  

   cylindrical, 
  of 
  uniform 
  diameter. 
  The 
  recurved 
  parts 
  of 
  the 
  tubes 
  

   and 
  the 
  mesopores 
  have 
  very 
  thick 
  vesicular 
  walls 
  in 
  confirmation 
  of 
  

   Gregory's 
  figure 
  61. 
  Gemmation 
  takes 
  place 
  especially 
  in 
  the 
  vicin- 
  

   ity 
  of 
  the 
  central 
  axis. 
  

  

  The 
  tangential 
  section 
  shows 
  small 
  scattered 
  mesopores 
  embedded 
  

   in 
  the 
  zoarial 
  epitheca. 
  

  

  Occurrence. 
  — 
  Lower 
  Cretaceous: 
  Sainte-Croix, 
  Switzerland 
  (Valan- 
  

   gian) 
  ; 
  Berklingen, 
  Germany. 
  

  

  Plesioty 
  pes. 
  —Cat. 
  No. 
  69946, 
  U.S.N.M. 
  

  

  Genus 
  SPARSICAVEA 
  D'Orbigny 
  ,1853 
  

  

  SPARSICAVEA 
  IRREGULARIS 
  D'Orbigny, 
  1853 
  

  

  Plate 
  15, 
  figs. 
  11-14. 
  

   1853. 
  Sparsicavea 
  irregularis 
  D'Orbigny, 
  Paleontologie 
  fran- 
  

   caise, 
  Terrain 
  Cretac6, 
  vol. 
  5, 
  p. 
  949, 
  pi. 
  617, 
  figs. 
  

   5-7. 
  

  

  Measurements. 
  — 
  Diameter 
  of 
  aperture 
  0.07-0.08 
  

   mm.; 
  diameter 
  of 
  peristome, 
  0.12 
  mm.; 
  diameter 
  of 
  

   zoarium, 
  1-2 
  mm. 
  

  

  Structure. 
  — 
  Our 
  determination 
  is 
  exact, 
  as 
  our 
  

   specimens 
  are 
  rigorously 
  analogous 
  to 
  those 
  of 
  

   D 
  ; 
  Orbigny. 
  His 
  figure 
  is 
  not 
  altogether 
  exact, 
  as 
  

   admitted 
  by 
  himself, 
  the 
  unequal 
  spacing 
  of 
  the 
  

   peristomes 
  not 
  being 
  visible. 
  Our 
  photographs 
  

   show 
  this 
  feature 
  very 
  well. 
  Mesopores 
  are 
  rather 
  

   numerous; 
  they 
  are 
  infundibuliform 
  at 
  their 
  ex- 
  

   tremity 
  and 
  appear 
  consequently 
  smaller 
  in 
  tangen- 
  

   tial 
  section. 
  The 
  peristome 
  is 
  salient 
  and 
  thick. 
  

  

  The 
  longitudinal 
  section 
  shows 
  the 
  usual 
  feature 
  

   of 
  Sparsicavea, 
  namely 
  club-shaped 
  tubes, 
  peripheral 
  

   and 
  axial 
  gemmation, 
  parietal 
  mesopores 
  (=macu- 
  

   lae 
  of 
  Gregory) 
  , 
  with 
  very 
  thick 
  walls. 
  In 
  transverse 
  

   section 
  the 
  thickening 
  of 
  the 
  walls 
  of 
  the 
  mesopores 
  

   forms 
  a 
  regular 
  epithecal 
  zone. 
  

  

  All 
  the 
  known 
  ovicelled 
  species 
  with 
  Sparsicavea 
  characters 
  are 
  

   referred 
  to 
  the 
  genus 
  Parascosoecia, 
  but 
  until 
  the 
  ovicell 
  of 
  the 
  

   present 
  one 
  is 
  known 
  we 
  believe 
  it 
  best 
  to 
  refer 
  it 
  to 
  the 
  older 
  name. 
  

  

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

   Machoremenil 
  (Ardennes) 
  , 
  France. 
  

  

  Plesioty 
  pes. 
  —Cat. 
  No. 
  69947, 
  U.S.N.M. 
  

  

  Fig. 
  45.— 
  Sparsicavea 
  

   irregularis 
  D'Orbig- 
  

   ny, 
  1851. 
  A. 
  Trans- 
  

   verse 
  section, 
  X 
  16. 
  

   B. 
  Longitudinal 
  

   section, 
  X 
  16. 
  Low- 
  

   er 
  Cretaceous 
  (Ap- 
  

   tian): 
  Faringdon, 
  

   England 
  

  

  