﻿172 
  PROCEEDINGS 
  OF 
  THE 
  CALIFORNIA 
  

  

  is 
  attached 
  to 
  the 
  trunks 
  of 
  trees 
  by 
  a 
  large 
  silken 
  web, 
  not 
  less 
  than 
  half 
  an 
  

   inch 
  in 
  diameter. 
  

   Length, 
  0.80 
  inch. 
  

  

  Dr. 
  Blake 
  exhibited 
  the 
  fossil-tooth 
  of 
  a 
  species 
  of 
  Shark, 
  which 
  

   was 
  found 
  near 
  Martinez, 
  probablj 
  in 
  the 
  cretaceous 
  rocks. 
  The 
  

   tooth 
  belonged 
  to 
  a 
  species 
  of 
  Carcharodon^ 
  and 
  its 
  specific 
  charac- 
  

   ters 
  indicated 
  C. 
  suhauricularis 
  ; 
  when 
  entire, 
  this 
  tooth 
  probably 
  

   measured 
  five 
  inches 
  in 
  length 
  on 
  the 
  edges 
  and 
  three 
  and 
  a 
  half 
  

   inches 
  broad 
  ; 
  the 
  animal 
  to 
  which 
  the 
  tooth 
  belonged 
  quite 
  likely 
  

   measured 
  as 
  much 
  as 
  sixty 
  feet 
  in 
  length. 
  

  

  Mr. 
  Bloomer 
  read 
  the 
  following 
  : 
  

  

  Note 
  on 
  Alexia 
  setifer 
  and 
  its 
  Allies. 
  

  

  BY 
  J. 
  O. 
  COOPER, 
  M. 
  D. 
  

  

  In 
  vol. 
  IV 
  of 
  our 
  Proceedings, 
  pp. 
  150 
  and 
  171, 
  I 
  described 
  some 
  new 
  

   Californian 
  Mollusca 
  very 
  briefly, 
  and 
  referred 
  to 
  others 
  by 
  name, 
  as 
  " 
  soon 
  to 
  

   be 
  published 
  with 
  illustrations." 
  Having 
  some 
  months 
  before 
  sent 
  the 
  manu- 
  

   script 
  and 
  figures 
  to 
  the 
  American 
  Journal 
  of 
  Conchology, 
  Philadelphia, 
  I 
  

   supposed 
  that 
  they 
  would 
  be 
  published 
  before 
  the 
  notices 
  in 
  our 
  Proceedings. 
  

   It 
  happened, 
  however, 
  that 
  they 
  were 
  delayed 
  so 
  long 
  on 
  the 
  way 
  that 
  the 
  

   Journal 
  completed 
  its 
  seventh 
  volume 
  and 
  was 
  then 
  suspended, 
  the 
  Philadelphia 
  

   Academy 
  of 
  Sciences 
  assuming 
  the 
  publication 
  of 
  such 
  articles 
  as 
  had 
  been 
  

   published 
  by 
  the 
  Conchological 
  Section 
  in 
  the 
  form 
  of 
  a 
  special 
  journal. 
  It 
  

   thus 
  happened 
  that 
  the 
  notices 
  in 
  our 
  Proceedings 
  had 
  priority 
  of 
  publication 
  

   by 
  nearly 
  or 
  quite 
  six 
  months, 
  as 
  far 
  as 
  the 
  Alexia 
  is 
  concerned 
  ; 
  while 
  the 
  

   meeting 
  at 
  which 
  the 
  description 
  was 
  presented 
  took 
  place 
  six 
  months 
  before 
  its 
  

   publication. 
  The 
  other 
  species 
  referred 
  to 
  were 
  named 
  without 
  description, 
  at 
  

   a 
  meeting 
  held 
  Dec. 
  19th, 
  1870, 
  and 
  published 
  in 
  April, 
  1871, 
  fifteen 
  months 
  

   before 
  their 
  appearance 
  in 
  the 
  Philadelphia 
  Proceedings. 
  I 
  merely 
  refer 
  to 
  

   these 
  dates, 
  not 
  as 
  a 
  question 
  of 
  doubtful 
  priority, 
  but 
  to 
  show 
  why 
  no 
  reference 
  

   is 
  made 
  in 
  either 
  publication 
  to 
  the 
  other, 
  and 
  to 
  indicate 
  the 
  difficulties 
  a 
  

   describer 
  meets 
  with 
  in 
  having 
  his 
  work 
  published 
  two 
  thousand 
  miles 
  away. 
  

  

  Another 
  more 
  important 
  object 
  is, 
  to 
  explain 
  why 
  a 
  very 
  serious 
  error 
  may 
  

   have 
  been 
  committed 
  in 
  describing 
  the 
  Alexia 
  as 
  new. 
  The 
  latest 
  work 
  on 
  

   American 
  species 
  was 
  W. 
  G. 
  Binney's 
  compilation 
  on 
  " 
  Land 
  and 
  Freshwater 
  

   Shells," 
  Part 
  II, 
  Sept., 
  1865, 
  (Smithsonian 
  Institution, 
  "Washington, 
  Misc. 
  

   Coll., 
  No. 
  143), 
  which 
  was 
  supposed 
  to 
  contain 
  all 
  references 
  bearing 
  on 
  the 
  

   species 
  of 
  the 
  North 
  Atlantic, 
  together 
  with 
  full 
  descriptions. 
  It 
  appears, 
  

   however, 
  from 
  the 
  last 
  volume 
  of 
  " 
  Jeffreys' 
  British 
  Mollusca," 
  which 
  had 
  not 
  

  

  