﻿42 
  JUHl.IN-DAKNFELT, 
  ON 
  THE 
  DIAT0M3 
  OF 
  THE 
  BALTIC 
  SEA. 
  

  

  V. 
  Smitliii 
  Ralfs. 
  

  

  VH. 
  D. 
  B. 
  Pl. 
  XLI, 
  f. 
  2. 
  

  

  Still 
  more 
  common 
  tlian 
  the 
  last 
  species. 
  

  

  v. 
  Saxonica 
  (K.) 
  Grun. 
  

  

  S. 
  gracilis 
  Sm.; 
  VH. 
  D. 
  B. 
  Pl. 
  XLI. 
  fig. 
  3. 
  

  

  Harbour 
  of 
  Travemllnde 
  (Ostsee 
  Exp, 
  1871, 
  p. 
  177), 
  

   Gotland 
  : 
  Slite 
  (Cl. 
  Sv. 
  o. 
  N. 
  Diat.), 
  Klinteliamn, 
  Ostergarn 
  

   (Cl.), 
  Vaxholm 
  (Cl.). 
  

  

  v. 
  macrocephala 
  Geun. 
  

  

  VH. 
  D. 
  B. 
  Pl. 
  XLI, 
  f. 
  6. 
  

  

  Rathan 
  (Aret. 
  Diat. 
  p. 
  107). 
  

  

  v. 
  lanceolata 
  OM. 
  

  

  VH. 
  D. 
  B. 
  Pl. 
  XLI, 
  fig. 
  7. 
  

  

  Karlshamn, 
  Gotland: 
  Klintehamn. 
  

  

  S. 
  afjinis 
  KiJTZ. 
  

  

  Forms 
  belonging 
  to 
  this 
  section 
  are 
  utterly 
  common 
  in 
  

   the 
  Baltic. 
  They 
  vary 
  very 
  much. 
  The 
  striae 
  are 
  geuerally 
  

   iihout 
  14 
  — 
  18 
  in 
  0,01 
  mm., 
  very 
  seldom 
  less 
  than 
  12 
  or 
  more 
  

   than 
  18. 
  Thus 
  they 
  generally 
  belong 
  to 
  the 
  true 
  S. 
  affinis 
  

   K. 
  (str 
  12,5 
  — 
  18) 
  and 
  more 
  seldom 
  to 
  S. 
  parva 
  K. 
  or 
  S. 
  ta- 
  

   bulata 
  K. 
  These 
  two 
  last 
  mentioned 
  I 
  cannot 
  retain 
  as 
  di- 
  

   stinct 
  species, 
  as 
  they 
  are 
  distinguished 
  only 
  by 
  the 
  varying 
  

   number 
  of 
  striae. 
  No 
  more 
  can 
  I 
  consider 
  S. 
  fasciculata 
  K. 
  

   as 
  a 
  separate 
  species, 
  as 
  it 
  shoiild 
  be 
  characterized 
  only 
  by 
  

   somewhat 
  longer 
  striae, 
  but 
  these 
  vary 
  much 
  in 
  length, 
  as 
  

   US 
  in 
  density. 
  Generallv 
  the 
  more 
  broadly 
  lanceolate 
  forms 
  

   have 
  longer 
  striae. 
  

  

  Besides 
  the 
  variation 
  in 
  the 
  striae, 
  we 
  have 
  also 
  to 
  notice 
  

   a 
  such 
  one 
  in 
  the 
  outline 
  of 
  the 
  valves. 
  They 
  are 
  broadly 
  

   lanceolate, 
  linear-lanceolate, 
  or 
  linear. 
  The 
  valves 
  are 
  gra- 
  

   dually 
  tapering 
  into 
  subacute 
  or 
  somewhat 
  capitate 
  ends, 
  or 
  

   are 
  produced 
  into 
  longer 
  beaks. 
  

  

  Plate 
  V 
  shows 
  some 
  of 
  the 
  most 
  characteristic 
  forms 
  

   tliat 
  I 
  have 
  found 
  in 
  the 
  Baltic, 
  and 
  shows 
  distinctly 
  enough 
  

   tliat 
  they 
  cannot 
  be 
  divided 
  into 
  separate 
  species. 
  The 
  varr. 
  

   I 
  have 
  uoticed 
  are: 
  

  

  var. 
  genuina 
  incl. 
  v. 
  acuminata 
  Geun. 
  Pl. 
  III, 
  fig:s 
  23, 
  

   25, 
  26, 
  28, 
  32. 
  

  

  Valves 
  linear 
  or 
  linear-lanceolate, 
  ends 
  not 
  produced, 
  

   str. 
  12 
  — 
  18 
  in 
  0,01 
  mm. 
  Common 
  everywhere 
  in 
  the 
  Baltic. 
  

  

  