﻿34 
  JUHLIN-DANNFELT, 
  ON 
  THE 
  DIATOMS 
  OF 
  THE 
  BALTIC 
  sEA. 
  

  

  P. 
  candidum 
  ScHUM. 
  

   P. 
  Scalpellum 
  Pkitch. 
  

   P. 
  bistriahim 
  ScHUM. 
  

  

  Endosigma 
  Bréb. 
  

  

  E. 
  eximium 
  Thw. 
  

   VH. 
  D. 
  B. 
  Pl. 
  XXI, 
  fig. 
  2. 
  

  

  Veiy 
  rare. 
  In 
  sliglitly 
  brackish 
  water. 
  Upland: 
  Blidö, 
  

   Ratlian 
  (Cl.). 
  

  

  Amphiprora 
  Ehb. 
  

  

  A. 
  paludosa 
  Sm. 
  

  

  VH. 
  D. 
  B. 
  Pl. 
  XXII, 
  fig. 
  10. 
  

  

  Xot 
  rare: 
  Gotland: 
  Klintehamu, 
  Kalmar, 
  Vestervik, 
  Sö- 
  

   dermanland: 
  Hcäringe, 
  Helsingfors, 
  Hernösand 
  (Cl.), 
  Rathan 
  

   (Cl.), 
  Haparanda 
  (Cl.). 
  

  

  A. 
  duplex 
  DoNK. 
  

  

  VH. 
  D. 
  B. 
  Pl. 
  XXI, 
  fig. 
  15, 
  16. 
  

  

  Vestervik, 
  Kalmar, 
  Helsingfors. 
  

  

  A. 
  alata 
  Ehb. 
  

  

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

  

  ? 
  A. 
  plicata 
  Greg. 
  

  

  Greg. 
  Clyde 
  Pl. 
  IV, 
  fig. 
  57; 
  Aret. 
  Diat. 
  p. 
  65. 
  

  

  Frustules 
  deeply 
  constricted; 
  extremities 
  broad, 
  soraewliat 
  

   rounded; 
  inner 
  margin 
  of 
  the 
  valve 
  forms 
  a 
  double 
  bow. 
  

   No 
  longitudinal 
  sulci 
  to 
  be 
  seen 
  on 
  the 
  connecting 
  niem- 
  

   brane. 
  Valve 
  lanceolate, 
  acute; 
  transverse 
  striae 
  on 
  the 
  valves 
  

   and 
  tlie 
  connecting 
  membrane 
  16 
  in 
  0,01 
  mm., 
  consisting 
  of 
  

   puncta 
  that 
  also 
  form 
  longitudinal 
  lines, 
  18 
  in 
  0,01 
  ram. 
  

   Length 
  0,120—0,130 
  ram., 
  breadth 
  of 
  the 
  valve 
  0,019 
  mm. 
  

  

  I 
  am 
  not 
  quite 
  sure 
  that 
  the 
  form 
  that 
  I 
  have 
  found, 
  

   is 
  the 
  true 
  A. 
  plicata 
  Greg., 
  because 
  the 
  fig. 
  quoted 
  is 
  drawn 
  

   in 
  a 
  too 
  little 
  scale 
  and 
  shows 
  the 
  frustnle 
  only 
  in 
  front 
  

   view. 
  I 
  thcrefore 
  give 
  a 
  fig. 
  of 
  the 
  Baltic 
  form 
  Pl. 
  II, 
  fig. 
  18. 
  

  

  Rare: 
  Vestervik, 
  Kalmar. 
  

  

  Fam. 
  Ampliipleure89. 
  

  

  Amphipleura 
  K. 
  

   A. 
  pellucida 
  K. 
  

   A'H. 
  D. 
  B. 
  Pl. 
  XVII, 
  f. 
  14. 
  

  

  