Am.  Jour.  Fharm. 
Nov.,  iS8o. 
Japanese  Isinglass. 
SIS 
tions,  not  completely  gelatinized,  closely  resembling  this  species,  and 
the  presence  of  ovoid  cruciately  divided  tetraspores  exactly  like  thuse 
belonging  to  this  plant  confirmed  the  determination. 
GeUdium  polycladium^  KUtz. — This  was  found  in  the  form  of  frag- 
ments, often  very  well  preserved ,  and  distinguished  from  Gloiopeltis  by 
^he  intricate  character  of  the  filaments,  resembling  KUtzing's  figure  of 
the  plant,  /.  c.^  tom.  xlx.,  p.  9,  t.  xxiv. 
This  species  is  frequently  studded  with  the  pretty  diatom,  Arachnoi- 
discus  ornatus^  Surr,  which  is  abundantly  met  with  in  some  specimens  of 
Japan  isinglass,  and  by  the  presence  of  which  M.  Menier  detected  the 
marine  origin  of  some  commercial  currant  jelly. 
Nitophyllum  ? — Some  portions  presented  a  flat  frond  and  hexagonal 
areolation,  which  recalled  the  structure  of  Nitophyllum.  These,  how- 
ever, were  found  only  in  very  small  quantity,  and  in  a  badly  preserved 
state. 
Polysiphonia  tapinocarpa^  ISur. — This  alga  was  met  with  in  the  form 
of  little  sections  of  filaments,  consisting  of  short  joints  which,  on 
transverse  section,  showed  ten  siphons,  and  I  do  not  doubt  belong  to 
the  above  syecies,  as  figured  in  Algae  Japonicae,"  1870,  p.  37,  pi. 
XXV.,  B.     Some  fragments  of  Melobesia?  were  found  on  this  plant. 
Polysiphonia  jragilis^  Sur. — This  species  is  represented  by  Suringar  on 
the  same  plate  as  the  last,  fig.  A.  It  is  distinguished  from  the  last  by 
showing  only  five  tubes  in  the  transverse  section. 
Polysiphonia  parasitica^  Grev.— This  species  has  not  apparently  been 
yet  found  on  the  coast  of  Japan,  but  from  the  fragments  possessing 
eight  or  nine  siphons,  and  from  other  characters  which  were  well  pre- 
served in  the  specimen  examined,  there  can  be  but  little  doubt  that 
they  belong  to  the  above  species,  as  figured  by  Kiitz.,  /.  r,,  xiii.,  p.  9, 
t.  xxvi. 
Diatomacea. — I  have  found  a  large  number  of  species  belonging  to 
this  group,  but  especially  Arachnoidiscus  ornatus^  Ehr.,  described  and 
represented  by  M.  Suringar,  Algae  Jap.,"  fasc.  iii.,  p.  5,  pi.  i.,  and  by 
M.  Menier.i 
The  aboee  are  by  no  means  the  only  species  which  enter  into  the 
comp(;sition  of  Japanese  isinglass,  but  a  large  number  of  others,  which 
were  observed  to  be  different,  were  too  damaged  to  be  recognizable. 
The  two  forms  of  the  aiticle  seem  to  be  made  with  the  same  algae, 
^  C,  Menier,  "  Falsification  de  la  Gelee  de  Groiseille  du  Commerce  decouverte 
par  les  Diatomees,"  Nantes,  1879. 
