﻿art. 
  2i 
  CYCLOSTOMATOUS 
  BRYOZOA 
  CANU 
  AND 
  BASSLER 
  71 
  

  

  of 
  the 
  tubes 
  with 
  facettes 
  are 
  terminal, 
  orbicular, 
  with 
  a 
  peristome 
  

   thin 
  and 
  little 
  salient; 
  the 
  facettes 
  are 
  elongated, 
  hexagonal, 
  little 
  

   distinct. 
  

  

  Measurements. 
  — 
  Diameter 
  of 
  peristomes, 
  0.14-0.16 
  mm.; 
  diameter 
  

   of 
  orbicular 
  orifices, 
  0.10 
  mm.; 
  diameter 
  of 
  lozenge-shaped 
  orifices, 
  

   0.06-0.08 
  mm.; 
  diameter 
  of 
  branches, 
  1 
  mm. 
  

  

  Affinities. 
  — 
  This 
  new 
  species 
  differs 
  from 
  Ceriocava 
  multilamellosa 
  

   in 
  its 
  smaller 
  branches, 
  in 
  the 
  lozenge-shaped 
  tubes 
  without 
  facettes, 
  

   and 
  in 
  the 
  terminal 
  position 
  of 
  the 
  orifices 
  on 
  the 
  facettes. 
  

  

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

   Switzerland 
  (common) 
  . 
  

  

  Coty 
  pes. 
  —Cat. 
  No. 
  69924, 
  U.S.N.M. 
  

  

  DIPLOCAVA, 
  new 
  genus 
  

  

  Ceriocavidae 
  with 
  dimorphic 
  zooecia. 
  

  

  Genotype. 
  — 
  Diplocava 
  incondita, 
  new 
  species. 
  Lower 
  Cretaceous 
  

   (Neocomian). 
  In 
  this 
  genus 
  tubes 
  without 
  facettes 
  and 
  much 
  larger 
  

   dimensions 
  appear. 
  They 
  are 
  most 
  frequently 
  in 
  more 
  or 
  less 
  orbic- 
  

   ular 
  and 
  salient 
  groups; 
  rarely 
  they 
  are 
  scattered. 
  They 
  are 
  not 
  

   constant, 
  and 
  it 
  is 
  not 
  rare 
  to 
  discover 
  zoarial 
  fragments 
  which 
  lack 
  

   them. 
  The 
  determination 
  of 
  species 
  of 
  this 
  genus 
  is 
  therefore 
  very 
  

   difficult, 
  especially 
  on 
  isolated 
  specimens. 
  The 
  ovicell 
  has 
  not 
  yet 
  

   been 
  discovered. 
  

  

  DIPLOCAVA 
  INCONDITA, 
  new 
  species 
  

  

  Plate 
  10, 
  figs. 
  5-12 
  

  

  Description. 
  — 
  The 
  zoarium 
  is 
  free, 
  dichotomous, 
  in 
  unilamellar 
  

   fronds 
  or 
  in 
  irregularly 
  cylindrical, 
  multilamellar 
  fragments. 
  The 
  

   large 
  zooecia 
  are 
  always 
  open, 
  grouped 
  in 
  salient 
  orbicular 
  areas 
  

   which 
  are 
  separated 
  from 
  each 
  other 
  by 
  zones 
  of 
  small 
  zooecia 
  with 
  

   facettes. 
  The 
  facettes 
  are 
  hexagonal, 
  distinct, 
  separated 
  by 
  a 
  

   furrow, 
  convex, 
  smooth, 
  perforated 
  in 
  the 
  middle. 
  The 
  apertura 
  is 
  

   large, 
  orbicular, 
  surrounded 
  by 
  a 
  thin 
  and 
  salient 
  peristome. 
  The 
  

   ovicell 
  is 
  star-shaped, 
  with 
  four 
  branches, 
  placed 
  in 
  the 
  midst 
  of 
  the 
  

   large 
  tubes. 
  

  

  Measurements. 
  — 
  Diameter 
  of 
  aperture, 
  0.14 
  mm. 
  ; 
  diameter 
  of 
  peri- 
  

   stome, 
  0.20 
  mm.; 
  diameter 
  of 
  facettes, 
  0.30 
  mm.; 
  diameter 
  of 
  exter- 
  

   nal 
  orifice 
  of 
  large 
  tubes, 
  0.30 
  mm.; 
  diameter 
  of 
  external 
  orifice 
  of 
  

   small 
  tubes, 
  0.20 
  mm.; 
  diameter 
  of 
  the 
  large 
  branches, 
  5 
  mm. 
  

  

  Variations. 
  — 
  This 
  species 
  is 
  very 
  irregular 
  in 
  its 
  external 
  aspect. 
  

   We 
  have 
  observed 
  some 
  lamellar 
  fragments 
  simple 
  or 
  double 
  with 
  

   monomorphic 
  zooecia, 
  arborescent 
  fragments 
  formed 
  of 
  small 
  tubes 
  

   only, 
  fragments 
  formed 
  of 
  tubes 
  with 
  facettes 
  only, 
  irregular 
  frag- 
  

   ments 
  formed 
  of 
  an 
  inner 
  trunk 
  of 
  zooecia 
  with 
  facettes, 
  covered 
  

  

  