﻿/O 
  Boyfr: 
  Rare 
  species 
  of 
  

  

  This 
  form, 
  of 
  which 
  several 
  specimens 
  have 
  been 
  found, 
  occurs 
  

   in 
  material 
  sent 
  me 
  by 
  Mr. 
  Robert 
  Hagelstein, 
  of 
  Mineola, 
  

   Long 
  Island, 
  after 
  whom 
  I 
  take 
  pleasure 
  in 
  naming 
  it. 
  

  

  Nitzschia 
  semicostata 
  sp. 
  nov. 
  

  

  Valves 
  constricted 
  in 
  the 
  middle, 
  cuneate 
  and 
  acute 
  at 
  the 
  

   ends. 
  Longitudinal 
  fold 
  well 
  defined. 
  Keel 
  puncta 
  seven 
  in 
  

   lOju, 
  extended 
  into 
  coarse 
  costae 
  to 
  half 
  the 
  width 
  of 
  the 
  valve, 
  

   to 
  lO/i 
  in 
  length. 
  Striae 
  fourteen 
  in 
  lOju, 
  punctate. 
  Length 
  of 
  

   valve 
  115 
  At, 
  [Fig. 
  6.] 
  

  

  Type 
  locality: 
  Campeche 
  Bay, 
  Mexico. 
  

  

  Distribution: 
  marine; 
  known 
  from 
  the 
  type 
  locaHty 
  only; 
  

  

  rare. 
  

  

  N. 
  suhcostata 
  Grun., 
  from 
  

  

  length 
  of 
  the 
  costae. 
  

  

  Surirella 
  Palmeri 
  sp. 
  nov. 
  

   Frustule 
  subcuneate, 
  rounded 
  at 
  the 
  ends. 
  Valves 
  ovate- 
  

  

  + 
  

  

  oblong. 
  Median 
  line 
  well 
  defined. 
  Costae 
  three 
  in 
  10 
  ju. 
  reaching 
  

   the 
  median 
  line, 
  indistinct. 
  Near 
  the 
  broad 
  end 
  of 
  the 
  valve 
  a 
  

  

  triangul 
  

  

  somewhat 
  obliauelv 
  from 
  the 
  median 
  

  

  Length 
  of 
  valve 
  io8 
  /<. 
  [Figs. 
  14, 
  15.] 
  

  

  Type 
  locality: 
  Wawaset, 
  Pennsylvania. 
  

  

  Distribution 
  : 
  fresh 
  water, 
  known 
  from 
  the 
  type 
  locality 
  only, 
  

   where 
  it 
  is 
  not 
  rare. 
  

  

  naming 
  this 
  form 
  after 
  M 
  

  

  Media. 
  P 
  

  

  Kitton* 
  has 
  described 
  and 
  figured 
  Surirella 
  Capronii 
  as 
  

   resembling 
  5. 
  splendida 
  (Ehrenb.) 
  Kutz. 
  in 
  outline 
  and 
  costae 
  but 
  

   differing 
  in 
  possessing 
  at 
  one 
  or 
  both 
  ends 
  a 
  "nipple-like 
  process," 
  

   hollow 
  at 
  the 
  base, 
  "with 
  a 
  short 
  spine 
  on 
  the 
  apex." 
  In 
  the 
  

  

  resemble 
  

  

  Kitton 
  

  

  from 
  that 
  of 
  S. 
  Capronii 
  

  

  species 
  of 
  Surirella 
  valves 
  occur 
  with 
  a 
  olasma 
  

  

  not, 
  however, 
  on 
  the 
  median 
  line. 
  The 
  pore 
  appear 
  

   medium 
  of 
  attachment 
  to 
  surrounding 
  objects 
  and 
  ^ 
  

   the 
  usual 
  slow 
  movement 
  of 
  the 
  frustule. 
  Whethe 
  

  

  serve 
  

  

  * 
  Science 
  Gossip 
  5: 
  61. 
  1869. 
  

  

  