﻿66 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.67 
  

  

  cent, 
  arranged 
  in 
  transverse 
  rows 
  (fig. 
  2) 
  and 
  more 
  rarely 
  in 
  

   quincunx 
  (fig. 
  6) 
  . 
  Opercula 
  are 
  frequent 
  (fig. 
  2) 
  . 
  

  

  The 
  eleocellaria 
  are 
  ordinary 
  zooecia 
  in 
  which 
  the 
  aperture 
  is 
  

   elongated 
  and 
  presents 
  two 
  lateral 
  denticles 
  (fig. 
  4). 
  

  

  The 
  chief 
  characteristic 
  of 
  this 
  species 
  is 
  the 
  frequent 
  presence 
  of 
  

   a 
  tranverse 
  fossette 
  placed 
  below 
  the 
  aperture 
  (fig. 
  5). 
  The 
  fusion 
  

   of 
  this 
  fossette 
  with 
  the 
  aperture 
  engenders 
  the 
  eleocellarium 
  

   (fig. 
  4) 
  . 
  The 
  longitudinal 
  section 
  of 
  this 
  species 
  has 
  been 
  figured 
  by 
  

   Gregory, 
  1899. 
  The 
  ovicell 
  is 
  unknown. 
  Figure 
  7 
  represents 
  

   an 
  arrest 
  of 
  development, 
  resulting 
  in 
  a 
  false 
  base. 
  

  

  Measurements. 
  — 
  

  

  A 
  . 
  fha 
  = 
  0.16-0.18 
  mm.) 
  ^ 
  ,. 
  [hf 
  = 
  0.44 
  mm. 
  

  

  Aperture 
  {-, 
  n 
  on 
  } 
  Jbacettes 
  <-, 
  f 
  n 
  AA 
  m 
  

  

  1 
  [la 
  = 
  0.20 
  mm. 
  J 
  [11 
  = 
  0.44 
  mm. 
  

  

  Diameter 
  of 
  the 
  branches, 
  3 
  mm. 
  

  

  Affinities. 
  — 
  This 
  species 
  is 
  very 
  well 
  characterized 
  by 
  the 
  nature 
  

   of 
  its 
  eleocellaria 
  and 
  by 
  the 
  transverse 
  fossettes 
  which 
  adorn 
  a 
  cer- 
  

   tain 
  number 
  of 
  zooecia. 
  

  

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

   (common) 
  . 
  

  

  Plesiotype.—C&t. 
  No. 
  69917, 
  U.S.N.M. 
  

  

  MELICERITITES 
  SEMICLAUSA 
  Gregory, 
  1899 
  

  

  Plate 
  11, 
  figs. 
  12, 
  13 
  

  

  1872. 
  Meliceritites 
  gracilis 
  Reuss, 
  Die 
  Bryozoen 
  und 
  Foraminiferen 
  des 
  unteren 
  

   Planers, 
  Paleontographica, 
  vol. 
  20, 
  pt. 
  1, 
  p. 
  120, 
  pi. 
  29, 
  figs. 
  12-16 
  (not 
  

   synonymy) 
  . 
  

  

  1899. 
  Meliceritites 
  semiclausa 
  (part) 
  Gregory, 
  Catalogue 
  of 
  the 
  Cretaceous 
  

   Bryozoa 
  in 
  the 
  British 
  Museum, 
  vol. 
  1, 
  p. 
  328, 
  pi. 
  14, 
  fig. 
  2 
  (not 
  figs. 
  1, 
  3). 
  

  

  Affinities. 
  — 
  Our 
  examples 
  correspond 
  almost 
  exactly 
  in 
  aspect 
  and 
  

   measurements 
  with 
  the 
  specimen 
  figured 
  by 
  Gregory 
  (pi. 
  14, 
  fig. 
  2), 
  

   the 
  single 
  slight 
  difference 
  being 
  in 
  the 
  more 
  elongate 
  form 
  of 
  the 
  

   eleocellarium. 
  

  

  The 
  ovicell 
  belongs 
  to 
  the 
  group 
  of 
  Meliceritites 
  transversa 
  in 
  its 
  

   great 
  width. 
  Unfortunately, 
  the 
  ovicell 
  of 
  our 
  figured 
  specimen 
  was 
  

   broken. 
  

  

  The 
  species 
  differs 
  from 
  Lobosoecia 
  semiclausa 
  Michelin, 
  1845, 
  in 
  

   its 
  much 
  larger 
  micrometric 
  measurements, 
  in 
  the 
  presence 
  of 
  an 
  

   eleocellarium, 
  and 
  in 
  its 
  semicircular 
  aperture. 
  

  

  Measurements. 
  — 
  

  

  A 
  [ha=? 
  1 
  ™ 
  ,, 
  fhf 
  = 
  0.40-0.48 
  mm. 
  

  

  Aperture 
  | 
  lft 
  =012 
  _ 
  0-16 
  mm 
  .| 
  Facettes 
  | 
  lf 
  =027 
  _ 
  0>30 
  mm 
  . 
  

  

  Diameter 
  of 
  large 
  branches, 
  2 
  mm. 
  

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

   (rare) 
  . 
  

  

  