﻿FROM 
  THE 
  CAMBRIAN 
  STRATA 
  OF 
  NORTH 
  AMERICA, 
  ETC. 
  135 
  

  

  Archceocyathus 
  in 
  the 
  character 
  of 
  the 
  outer 
  and 
  inner 
  wall-plates 
  

   and 
  of 
  the 
  septa, 
  but 
  possessing 
  in 
  addition 
  transverse 
  cribriform 
  

   plates, 
  which 
  subdivide 
  the 
  vertical 
  interseptal 
  loculi. 
  These 
  trans- 
  

   verse 
  plates, 
  which 
  may 
  be 
  compared 
  to 
  the 
  tabulae 
  in 
  fossil 
  corals, 
  

   only 
  that 
  they 
  are 
  perforate, 
  extend 
  quite 
  across 
  the 
  space 
  between 
  

   the 
  outer 
  and 
  inner 
  laminae 
  of 
  the 
  wall, 
  but 
  they 
  do 
  not 
  extend 
  into 
  

   the 
  interior 
  hollow 
  cup. 
  In 
  some 
  cases 
  they 
  are 
  nearly 
  horizontal, 
  

   in 
  others 
  they 
  are 
  arched 
  or 
  even 
  oblique. 
  In 
  structure 
  they 
  re- 
  

   semble 
  the 
  vertical 
  septa, 
  and 
  in 
  some 
  sections 
  can 
  scarcely 
  be 
  dis- 
  

   tinguished 
  from 
  them. 
  

  

  Dr. 
  Bornemann 
  has 
  described 
  15 
  species 
  of 
  this 
  genus 
  from 
  the 
  

   Cambrian 
  strata 
  of 
  Sardinia; 
  the 
  differences 
  between 
  them 
  are 
  

   principally 
  those 
  of 
  size 
  and 
  form 
  and 
  the 
  number 
  of 
  septa 
  and 
  cross- 
  

   septa 
  or 
  tabulae. 
  Mr. 
  Walcott 
  * 
  has 
  likewise 
  described 
  a 
  species 
  

   evidently 
  belonging 
  to 
  this 
  genus, 
  under 
  the 
  name 
  of 
  ArchcEOcyathus 
  

   Billingsi 
  t. 
  It 
  comes 
  from 
  the 
  Lower 
  Cambrian 
  of 
  the 
  Anse 
  au 
  Loup, 
  

   Labrador. 
  

  

  Genus 
  Anthomorpha, 
  Bornemann. 
  

  

  (1884. 
  Zeitschr. 
  d. 
  deutsch. 
  geol. 
  Gesellsch. 
  p. 
  705 
  ; 
  Yer- 
  

   steinerungen 
  Sardiniens, 
  p. 
  75.) 
  

  

  This 
  genus 
  has 
  been 
  constituted 
  for 
  cup-shaped 
  or 
  turbinate 
  

   forms 
  with 
  robust 
  vertical 
  septa, 
  dissepiments, 
  and 
  transverse 
  plates 
  

   or 
  tabulae. 
  These 
  structures 
  are 
  stated 
  to 
  be 
  non-perf 
  orate 
  and 
  thus 
  

   to 
  form 
  a 
  transition 
  to 
  the 
  true 
  corals. 
  

  

  In 
  the 
  material 
  sent 
  to 
  me 
  by 
  Dr. 
  Bornemann 
  from 
  Sardinia, 
  

   I 
  have 
  only 
  seen 
  two 
  specimens 
  which 
  could 
  be 
  referred 
  to 
  this 
  

   genus, 
  and 
  in 
  these 
  the 
  septal 
  walls 
  had 
  been 
  replaced 
  by 
  calcite, 
  

   so 
  that 
  one 
  could 
  not 
  determine 
  whether 
  they 
  were 
  originally 
  im- 
  

   perforate 
  or 
  not. 
  Only 
  a 
  single 
  species 
  from 
  Sardinia 
  has 
  been 
  

   referred 
  to 
  this 
  genus 
  by 
  Dr. 
  Bornemann. 
  

  

  Genus 
  Protopharetra, 
  Bornemann. 
  (Plate 
  V. 
  fig. 
  11.) 
  

  

  (1883. 
  Zeitschr. 
  d. 
  deutsch. 
  geol. 
  Gesellsch. 
  p. 
  274 
  ; 
  id. 
  1884, 
  

   pp. 
  400, 
  705 
  ; 
  Versteinerungen 
  Sardiniens, 
  pp. 
  38, 
  39, 
  46.) 
  

  

  No 
  categorical 
  definition 
  of 
  this 
  genus 
  has 
  been 
  given, 
  for 
  the 
  

   author 
  did 
  not 
  regard 
  it 
  as 
  an 
  independent 
  organism, 
  but 
  merely 
  

   the 
  lower 
  or 
  vegetative 
  state 
  of 
  development 
  of 
  forms 
  of 
  Archceocya- 
  

   ihus 
  and 
  Coscinocyathus. 
  Some 
  forms 
  of 
  these 
  genera 
  can 
  be 
  traced, 
  

   according 
  to 
  the 
  author, 
  to 
  an 
  early 
  stage, 
  in 
  which 
  they 
  exhibit 
  the 
  

   skeletal 
  structure 
  of 
  Protopharetra. 
  In 
  other 
  cases, 
  however, 
  only 
  

   this 
  Protopharetra 
  stage 
  is 
  present, 
  and 
  no 
  connexion 
  with 
  the 
  

  

  * 
  Bull. 
  no. 
  30, 
  p. 
  74, 
  pi. 
  iii. 
  figs. 
  3, 
  3 
  a-c. 
  

  

  t 
  From 
  an 
  examination 
  of 
  the 
  type 
  of 
  this 
  species 
  (kindly 
  sent 
  me 
  by 
  Mr. 
  

   Walcott), 
  I 
  believe 
  that 
  the 
  " 
  spicula-like- 
  bodies 
  " 
  referred 
  to 
  in 
  his 
  description 
  

   are 
  fibres 
  of 
  calcite 
  similar 
  to 
  those 
  described 
  by 
  Bornemann 
  in 
  Coscinocyathus 
  

   vesica 
  and 
  C. 
  profeus 
  (Verst. 
  Sardin. 
  p. 
  71). 
  They 
  are 
  not, 
  in 
  my 
  opinion, 
  

   sponge-spicules, 
  — 
  (G. 
  J. 
  H., 
  Jan. 
  24, 
  1889.) 
  

  

  