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  ORMOCERAS 
  REMOTISEPTUM, 
  (n. 
  species.) 
  

   Plate 
  4, 
  fig. 
  3. 
  

  

  Cylindrical, 
  gradually 
  tapering 
  ; 
  septa 
  moderately 
  convex, 
  distant 
  

   half 
  the 
  diameter 
  of 
  the 
  tube 
  ; 
  siphuncle 
  excentric, 
  large, 
  swelling 
  

   moderately 
  between 
  the 
  septa, 
  and 
  but 
  slightly 
  contracted 
  at 
  the 
  junc- 
  

   tion 
  of 
  the 
  septa 
  ; 
  character 
  of 
  the 
  external 
  surface 
  unknown. 
  

  

  The 
  specimen 
  described 
  is 
  a 
  fragment 
  which 
  is 
  worn 
  down 
  through 
  

   the 
  centre 
  of 
  the 
  siphuncle. 
  The 
  proportions 
  of 
  this 
  part 
  of 
  the 
  fossil 
  

   and 
  the 
  great 
  distance 
  of 
  the 
  septa 
  contrast 
  very 
  strongly 
  with 
  the 
  

   Ormoceras 
  tenuifilum 
  and 
  with 
  the 
  other 
  known 
  species 
  of 
  the 
  genus. 
  

  

  This 
  species 
  occurs 
  in 
  the 
  higher 
  part 
  of 
  the 
  Trenton 
  limestone, 
  near 
  

   Watertown, 
  Jefferson 
  county. 
  . 
  {State 
  Collection.) 
  

  

  ENDOCERAS 
  LATIVENTRUM, 
  (n. 
  species.) 
  

   Plate 
  5, 
  fig. 
  1, 
  a, 
  b. 
  

  

  Cylindric 
  or 
  conical, 
  somewhat 
  rapidly 
  tapering, 
  septa 
  veiy 
  slightly 
  

   convex, 
  distant 
  from 
  each 
  other 
  about 
  one-sixth 
  of 
  the 
  diameter 
  of 
  the 
  

   tube 
  ; 
  siphuncle 
  large, 
  entirely 
  lateral, 
  diameter 
  towards 
  the 
  smaller 
  

   extremity 
  greater 
  than 
  one-third 
  the 
  diameter 
  of 
  the 
  entire, 
  tube 
  j 
  em- 
  

   bryo 
  tube 
  smooth, 
  slender 
  towards 
  the 
  smaller 
  extremity. 
  

  

  This 
  species 
  is 
  easily 
  distinguished 
  from 
  the 
  E. 
  proteiforme 
  in 
  any 
  of 
  

   its 
  stages 
  by 
  the 
  more 
  rapid 
  diminution 
  of 
  the 
  tube, 
  by 
  the 
  entirely 
  lat- 
  

   eral 
  position 
  of 
  the 
  siphuncle, 
  and 
  the 
  closer 
  arrangement 
  of 
  the 
  septa. 
  

   The 
  fragment 
  described 
  is 
  something 
  more 
  than 
  a 
  foot 
  in 
  length, 
  and 
  is 
  

   from 
  the 
  central 
  part 
  of 
  the 
  individual, 
  neither 
  the 
  apex 
  or 
  outer 
  cham- 
  

   ber 
  being 
  preserved. 
  The 
  embryo 
  tube, 
  which 
  is 
  visible 
  near 
  the 
  apex, 
  

   is 
  slender 
  and 
  gradually 
  tapering. 
  

  

  Fig. 
  1 
  a. 
  The 
  specimen 
  natural 
  size, 
  showing 
  the 
  embryo 
  tube 
  above 
  

   'the 
  middle. 
  

  

  Fig. 
  1 
  b. 
  A 
  section 
  showing 
  the 
  position 
  and 
  size 
  of 
  the 
  siphuncle. 
  

  

  This 
  species 
  occurs 
  in 
  the 
  lower 
  part 
  of 
  the 
  Trenton 
  limestone, 
  near 
  

   Lowville, 
  in 
  Lewis 
  county. 
  The 
  only 
  specimen 
  known 
  is 
  the 
  one 
  here 
  

   described, 
  which 
  is 
  placed 
  in 
  the 
  State 
  collection. 
  

  

  COLPOCERAS, 
  (new 
  genus.) 
  

  

  Gr. 
  xoXtfos, 
  sinus, 
  and 
  xepas, 
  cornu, 
  in 
  allusion 
  to 
  the 
  deep 
  sinus 
  in 
  the 
  

   septa. 
  

  

  Cylindrical 
  or 
  sub-cylindrical, 
  septa 
  oblique 
  to 
  the 
  axis 
  of 
  the 
  shell, 
  

   regularly 
  arched 
  on 
  the 
  dorsal 
  side, 
  and 
  bending 
  downwards 
  in 
  a 
  deep 
  

   sinus 
  towards 
  the 
  mouth 
  on 
  the 
  ventral 
  side. 
  

  

  