﻿CYCLOSTOMATOUS 
  BRYOZOA 
  CANU 
  AND 
  BASSLER 
  

  

  73 
  

  

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

   zerland 
  (common.) 
  

  

  Coty 
  pes. 
  —Gut. 
  No. 
  69925, 
  U.S.N.M. 
  

  

  DIPLOCAVA 
  INORDINATA, 
  new 
  species 
  

  

  Plate 
  11, 
  figs. 
  1-5 
  

  

  Description. 
  — 
  The 
  zoarium 
  is 
  free, 
  cylindrical, 
  arborescent; 
  the 
  

   base 
  is 
  enlarged 
  and 
  placed 
  on 
  a 
  substratum. 
  The 
  large 
  tubes 
  

   appear 
  very 
  irregularly 
  among 
  the 
  others, 
  sometimes 
  isolated, 
  some- 
  

   times 
  grouped. 
  The 
  facettes 
  are 
  hexagonal, 
  little 
  visible, 
  smooth, 
  

   very 
  little 
  convex, 
  perforated 
  at 
  the 
  middle 
  by 
  the 
  aperture. 
  The 
  

   aperture 
  is 
  orbicular, 
  large 
  or 
  small, 
  according 
  to 
  the 
  nature 
  of 
  the 
  

   tubes, 
  surrounded 
  by 
  a 
  peristome 
  which 
  is 
  scarcely 
  salient 
  and 
  very 
  

   thin. 
  The 
  orifices 
  of 
  the 
  tubes 
  without 
  

   facettes 
  are 
  polygonal. 
  

  

  Measurements. 
  — 
  Inner 
  orifice 
  of 
  small 
  

   tubes, 
  0.16 
  mm.; 
  diameter 
  exterior 
  orifice 
  

   of 
  small 
  tubes, 
  0.20 
  mm.; 
  diameter 
  inner 
  

   orifice 
  of 
  large 
  tubes, 
  0.20-0.24 
  mm.; 
  diam- 
  

   eter 
  exterior 
  orifice 
  of 
  large 
  tubes, 
  0.30 
  

   mm.; 
  diameter 
  aperture, 
  small 
  tubes 
  with 
  

   facettes, 
  0.10 
  mm.; 
  diameter 
  aperture, 
  large 
  

   tubes 
  with 
  facettes, 
  0.14 
  mm.; 
  diameter 
  of 
  

   the 
  large 
  branches, 
  3 
  mm. 
  

  

  Variations. 
  — 
  As 
  our 
  specimens 
  are 
  numer- 
  

   ous, 
  we 
  have 
  been 
  able 
  to 
  study 
  the 
  varia- 
  

   tions. 
  We 
  have 
  observed 
  zoarial 
  fragments 
  

   formed 
  uniquely 
  of 
  large 
  (fig. 
  3) 
  or 
  small 
  

   (fig. 
  2) 
  zooecia, 
  fragments 
  with 
  both 
  kinds 
  

   of 
  zooecia 
  (fig. 
  4), 
  and 
  finally 
  a 
  fragment 
  

   with 
  tubes 
  bearing 
  facettes 
  (fig. 
  5) 
  . 
  

  

  In 
  longitudinal 
  sections 
  the 
  tubes 
  have 
  a 
  diameter 
  quite 
  variable 
  

   in 
  their 
  recurved 
  expanded 
  parts. 
  

  

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

   Switzerland 
  (common) 
  . 
  

  

  Coty 
  pes. 
  —Cat. 
  No. 
  69926, 
  U.S.N.M. 
  

  

  DIPLOCAVA 
  ORBICULIFERA, 
  new 
  species 
  

  

  Plate 
  11, 
  figs. 
  6-8 
  

  

  Description. 
  — 
  The 
  zoarium 
  is 
  free, 
  cylindrical, 
  ramose. 
  The 
  large 
  

   tubes 
  are 
  grouped 
  in 
  very 
  regular 
  orbicular 
  areas 
  irregularly 
  arranged 
  

   on 
  the 
  zoarium. 
  The 
  small 
  tubes 
  are 
  much 
  more 
  numerous, 
  hexag- 
  

   onal, 
  arranged 
  in 
  quincunx. 
  

  

  Measurements. 
  — 
  Diameter 
  orifice 
  of 
  small 
  tubes, 
  0.10 
  mm.; 
  diam- 
  

   eter 
  of 
  large 
  tubes, 
  0.20 
  mm. 
  ; 
  diameter 
  of 
  zoarium, 
  10 
  mm. 
  

  

  Fig. 
  37. 
  — 
  Diplocava 
  inordinata, 
  new 
  

   species. 
  Longitudinal 
  section, 
  

   X 
  16, 
  exhibiting 
  the 
  variations 
  in 
  

   diameter 
  of 
  the 
  tubes 
  at 
  their 
  

   extremity. 
  Lower 
  Cretaceous 
  

   (Valangian): 
  Sainte-Croix, 
  

   Switzerland 
  

  

  