﻿48 
  JUHLIN-DANNFELT, 
  ON 
  THE 
  DIATOMS 
  OF 
  THE 
  BALTIC 
  SEA. 
  

  

  Subfoss.: 
  in 
  enorraous 
  masses 
  in 
  bathingslick 
  from 
  Ronneby, 
  

   in 
  silt 
  from 
  the 
  peat 
  mosses 
  in 
  Roslagen. 
  

  

  Diam. 
  15 
  — 
  30 
  /'. 
  On 
  all 
  the 
  specimens 
  that 
  I 
  have 
  

   examined, 
  I 
  never 
  could 
  trace 
  any 
  sculpture, 
  save 
  -thc 
  irre- 
  

   gularly 
  spotted 
  central 
  iimbilicus. 
  Crippled 
  form 
  of 
  Hyalod. 
  

   subtilis 
  Bail, 
  tbat 
  cliaracterises 
  tbe 
  Arctic 
  Ocean 
  (?) 
  

  

  Cyclotella 
  K. 
  

  

  C. 
  Menegliiniana 
  K. 
  

   Cl. 
  & 
  Moll. 
  Diat. 
  N:o 
  173. 
  

  

  Rather 
  rare 
  in 
  tlie 
  southern 
  part 
  of 
  the 
  Baltic: 
  Malmö. 
  

   More 
  common 
  nortli 
  of 
  the 
  Kalmar 
  Sound. 
  Common 
  

   on 
  the 
  coast 
  of 
  Upland 
  and 
  in 
  the 
  Finnish 
  bay. 
  

  

  C. 
  operculata 
  K. 
  

   Sm. 
  Syn. 
  Pl. 
  V, 
  fig. 
  48. 
  

  

  Freshwater 
  species 
  occurring 
  in 
  slightly 
  brackish 
  water: 
  

   Gotland: 
  Fårön 
  (Cl.), 
  Vaxholm 
  (Cl.), 
  Norrtelje. 
  

  

  Stephanodiscus. 
  

  

  S. 
  Astroea 
  (Ehb.) 
  Geun. 
  

   Cyclotella 
  Rotula 
  Sm. 
  Syn. 
  Pl. 
  V, 
  fig. 
  50. 
  

   In 
  almost 
  fresh 
  water: 
  Travemllnde, 
  Södermanland: 
  Hä- 
  

   ringe, 
  Norrtelje. 
  

  

  S. 
  Bo^amaputrce 
  Ehb. 
  

  

  Unknown 
  to 
  me. 
  In 
  the 
  Baltic 
  (Schum. 
  1862). 
  

  

  Fam. 
  Melosirese. 
  

  

  Melosira 
  Ag. 
  

  

  M. 
  Borreri 
  Grev. 
  

  

  Sm. 
  Syn. 
  Vol. 
  II, 
  pag. 
  56, 
  Pl. 
  L, 
  fig. 
  330. 
  

  

  Only 
  in 
  really 
  brackish 
  water. 
  Rather 
  rare. 
  Öresund, 
  

   Traveraiinde, 
  Kalmar, 
  Västervik, 
  Helsingfors. 
  

  

  Subfossil: 
  Ronneby 
  bathing 
  silt 
  (utterly 
  common). 
  

  

  v. 
  hothnica 
  Geun. 
  

  

  Length 
  of 
  the 
  frustule 
  greater 
  in 
  proportion 
  to 
  tlic 
  

   breadth, 
  a 
  little 
  inflexion 
  in 
  the 
  ontline 
  of 
  the 
  side 
  of 
  the 
  

   valve. 
  Intermediate 
  form 
  to 
  the 
  next 
  spec. 
  

  

  