﻿144 
  DE. 
  G. 
  J. 
  H.IXDE 
  OX 
  ARCELEOCYATH.TTS 
  AND 
  OTHER 
  GEXERA 
  

  

  Genus 
  CALATHnnir, 
  Billings. 
  

   (1865. 
  Pal. 
  Fossils, 
  vol. 
  i. 
  pp. 
  208, 
  209.) 
  

  

  Sponges 
  inverted 
  conical 
  or 
  subcylindrical, 
  with 
  large 
  cloacal 
  

   cavity. 
  The 
  walls 
  perforated 
  by 
  closely-set, 
  circular, 
  or 
  oval 
  canal- 
  

   apertures, 
  disposed 
  so 
  as 
  to 
  form 
  nearly 
  horizontal 
  and 
  longitudinally 
  

   spiral 
  lines. 
  Spicular 
  structure 
  unknown. 
  

  

  This 
  genus 
  is 
  based 
  on 
  Cdlaihium 
  formosum, 
  Bill. 
  * 
  ; 
  the 
  type 
  

   specimen 
  is 
  inverted 
  conical, 
  46 
  millim. 
  in 
  height 
  and 
  24 
  millim. 
  in 
  

   width 
  at 
  the 
  summit. 
  The 
  outer 
  surface 
  is 
  quite 
  weathered 
  out 
  of 
  

   the 
  rock, 
  but 
  the 
  interior 
  is 
  solidly 
  filled 
  with 
  a 
  dark 
  limestone 
  

   matrix, 
  The 
  canal-apertures 
  of 
  the 
  wall 
  are 
  about 
  1 
  millim. 
  in 
  

   diameter, 
  and 
  from 
  # 
  5 
  to 
  1 
  millim. 
  apart. 
  The 
  walls 
  are 
  not 
  more 
  

   than 
  3 
  or 
  4 
  millim. 
  in 
  thickness 
  ; 
  though 
  siliceous, 
  their 
  spicular 
  

   structure 
  has 
  been 
  entirely 
  obliterated, 
  so 
  that 
  whether 
  it 
  is 
  hexac- 
  

   tinellid 
  or 
  lithistid 
  cannot 
  be 
  known 
  from 
  the 
  type 
  specimen. 
  This 
  

   is 
  from 
  the 
  Calciferous 
  Formation 
  (Division 
  G 
  of 
  Billings) 
  at 
  Cape 
  

   Norman, 
  Newfoundland 
  ?. 
  

  

  Calathitth 
  Axstedi, 
  Billings. 
  

  

  1865. 
  C. 
  Anstedi, 
  Bill. 
  Pal. 
  Foss. 
  vol. 
  i. 
  p. 
  210, 
  fig. 
  194. 
  

  

  A 
  fragmentary 
  specimen 
  from 
  the 
  Durness 
  Limestone 
  of 
  Suther- 
  

   landshire 
  agrees 
  so 
  closely 
  with 
  Billings's 
  description 
  and 
  figure 
  of 
  

   this 
  species 
  that 
  it 
  may 
  safely 
  be 
  included 
  under 
  it, 
  The 
  fragment 
  

   is 
  the 
  upper 
  portion 
  of 
  a 
  turbinate 
  specimen 
  ; 
  the 
  walls 
  are 
  8 
  millim. 
  

   in 
  thickness, 
  and 
  the 
  cloacal 
  cavity 
  50 
  millim. 
  in 
  width. 
  The 
  canal- 
  

   apertures 
  of 
  the 
  surface 
  are 
  in 
  nearly 
  horizontal 
  and 
  vertical 
  rows 
  ; 
  

   they 
  are 
  smaller 
  than 
  in 
  0. 
  formosum, 
  being 
  about 
  4 
  in 
  5 
  millim. 
  

   No 
  traces 
  of 
  the 
  spicular 
  structure 
  remain. 
  The 
  form 
  described 
  by 
  

   Mr. 
  Billings 
  is 
  from 
  the 
  Calciferous 
  Formation 
  (Division 
  H), 
  

   Pistolet 
  Bay, 
  Schooner 
  Island, 
  Newfoundland. 
  

  

  Genus 
  Nepterella 
  J, 
  gen. 
  nov. 
  (Plate 
  V. 
  fig. 
  15.) 
  

  

  I 
  propose 
  this 
  genus 
  to 
  include 
  Calatliium 
  (?) 
  joaradoxicum§, 
  

   Billings, 
  with 
  the 
  following 
  generic 
  characters 
  : 
  — 
  Sponges 
  massive, 
  

   subcylindrical, 
  with 
  basal 
  expansion 
  ; 
  summit 
  truncate, 
  with 
  an 
  

   open, 
  shallow, 
  basin-like 
  depression. 
  Traces 
  of 
  canals 
  extending 
  

   from 
  the 
  surface 
  to 
  the 
  interior. 
  Skeleton, 
  a 
  close 
  meshwork 
  of 
  

   lithistid 
  spicules. 
  Spicules 
  rod-like, 
  with 
  branching 
  or 
  truncate 
  

   ends. 
  

  

  The 
  type 
  specimen, 
  which 
  is 
  now 
  of 
  solid 
  silica, 
  is 
  subcylindrical, 
  

   about 
  50 
  millim. 
  in 
  height 
  by 
  60 
  millim. 
  in 
  width, 
  with 
  an 
  uneven 
  

   expanded 
  base 
  ||. 
  The 
  basin-like 
  hollow 
  at 
  the 
  summit 
  is 
  not 
  more 
  

  

  * 
  Pal. 
  Foss. 
  vol. 
  i. 
  p. 
  209, 
  fig. 
  192. 
  

   t 
  Ibid. 
  vol. 
  i. 
  p. 
  371. 
  

   \ 
  vnrrrjp, 
  a 
  laver, 
  diniin. 
  

   § 
  Pal. 
  Foss. 
  vol. 
  i. 
  p. 
  358, 
  fig. 
  345. 
  

  

  | 
  In 
  the 
  figure 
  given 
  by 
  Air. 
  Billings 
  the 
  sponge 
  is, 
  in 
  my 
  opinion, 
  repre- 
  

   sented 
  upside 
  down. 
  

  

  