﻿X68 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  and 
  clean 
  casts 
  of 
  the 
  borings; 
  or 
  when 
  these 
  natural 
  conditions 
  

   are 
  reproduced 
  artificially 
  by 
  removing 
  the 
  calcareous 
  material 
  

   from 
  a 
  lime 
  shale. 
  

  

  Probably 
  the 
  first 
  attempt 
  to 
  characterize 
  with 
  a 
  definite 
  name 
  

   these 
  undoubted 
  sponge 
  borings 
  was 
  that 
  of 
  McCoy 
  [Brit. 
  Paleoz. 
  

   Foss. 
  1855. 
  p. 
  260, 
  pi. 
  iB, 
  fig. 
  1, 
  1 
  a] 
  who 
  illustrated 
  under 
  the 
  name 
  

   Vioa 
  prisca 
  a 
  series 
  of 
  simple 
  straight 
  club-shaped 
  casts 
  of 
  

   borings 
  occurring 
  in 
  the 
  shell 
  substance 
  of 
  the 
  pelecypod 
  identified 
  

   as 
  Pterinea 
  demissa 
  Conrad 
  of 
  the 
  Upper 
  Siluric. 
  It 
  is 
  

   probably 
  safer 
  not 
  to 
  designate 
  these 
  sponge 
  relics 
  by 
  the 
  name 
  of 
  

   any 
  genus 
  now 
  living 
  and 
  I 
  propose, 
  in 
  speaking 
  of 
  several 
  distinct 
  

   forms 
  of 
  them, 
  to 
  employ 
  the 
  term 
  Clionolithes. 
  

  

  The 
  straight 
  clavate 
  tubes 
  of 
  Clionolithes 
  priscus 
  

   (McCoy) 
  usually 
  originate 
  at 
  the 
  edge 
  of 
  a 
  dead 
  shell 
  and 
  expand 
  

   gently 
  inward 
  ; 
  probably 
  the 
  sponge 
  nested 
  at 
  the 
  club-shaped 
  ex- 
  

   tremity 
  of 
  the 
  hole, 
  drawing 
  the 
  water 
  currents 
  in 
  to 
  itself. 
  It 
  is 
  

   not 
  always 
  the 
  case 
  that 
  the 
  shell 
  was 
  dead 
  before 
  the 
  work 
  

   of 
  these 
  borers 
  began. 
  There 
  are 
  several 
  illustrations 
  given 
  here 
  

   to 
  show 
  that 
  a 
  brachiopod 
  or 
  pelecypod 
  may 
  have 
  been 
  attacked 
  

   by 
  these 
  sponges 
  at 
  any 
  growth 
  stage 
  and 
  that 
  after 
  the 
  attack 
  had 
  

   begun 
  the 
  growth 
  of 
  the 
  shell 
  continued. 
  There 
  is 
  a 
  curious 
  

   simultaneousness 
  in 
  the 
  attacks 
  of 
  these 
  pseudoparasites 
  — 
  all 
  

   started 
  in 
  at 
  once 
  and 
  frequently 
  one 
  such 
  attack 
  is 
  not 
  followed 
  

   by 
  others 
  [see 
  pi. 
  8, 
  fig. 
  2, 
  4]. 
  This 
  form, 
  C. 
  priscus, 
  was 
  quite 
  

   common 
  in 
  the 
  late 
  Siluric 
  and 
  very 
  abundant 
  throughout 
  the 
  

   Devonic. 
  

  

  Clionolithes 
  radicans 
  designates 
  a 
  quite 
  different 
  

   expression 
  of 
  this 
  boring 
  habit. 
  Here 
  the 
  tubes 
  radiate 
  and 
  branch 
  

   outward 
  from 
  a 
  center, 
  giving 
  a 
  decided 
  rootlike 
  expression 
  to 
  the 
  

   resultant 
  very 
  complicated 
  combination 
  of 
  tubes. 
  These 
  branch- 
  

   ing 
  tubes 
  often 
  unite, 
  fuse 
  or 
  anastomose 
  producing 
  a 
  somewhat 
  

   irregularly 
  reticulated 
  expression. 
  This 
  sponge 
  particularly 
  in- 
  

   fested 
  the 
  living 
  and 
  dead 
  shells 
  of 
  the 
  brachiopods, 
  finding 
  en- 
  

   trance 
  less 
  often 
  at 
  the 
  margin 
  than 
  through 
  the 
  pores 
  on 
  the 
  

   surface 
  of 
  the 
  shell. 
  The 
  complex 
  of 
  tubules 
  is 
  small 
  in 
  comparison 
  

   with 
  those 
  of 
  C. 
  priscus 
  and 
  it 
  is 
  not 
  unusual 
  to 
  find 
  both 
  of 
  

   these 
  forms 
  infesting 
  the 
  same 
  shell. 
  This 
  boring 
  sponge, 
  so 
  far 
  as 
  

   my 
  observation 
  extends, 
  is 
  restricted 
  to 
  the 
  Devonic. 
  

  

  Clionolithes 
  reptans 
  has 
  threadlike 
  vermiform 
  tubes 
  

   which 
  wander 
  loosely 
  and 
  at 
  random 
  through 
  the 
  shell 
  substance 
  

   of 
  both 
  brachiopods 
  and 
  pelecypods. 
  

  

  