In  our  examination  of  the  various  species  and  varieties  of
the  three  preceding  species,  we  are  much  disposed  to  con-
cur in  the  opinion  expressed  by  the  talented  author  of  the
"  Musci,"  in  the  '  Elora  Hibernica,'  who  says,  with  reference
to  them,  ''So  variable  in  the  breadth  of  the  leaves,  the
breadth  of  the  nerves,  which  are  sometimes  concealed  by  the
involute  edges  of  the  leaves,  and  by  the  length  of  the  ros-


TORTULA.  157

trum  of  the  lids,  that  1  feel  the  greatest  difficulty  in  com-
prehending the  T.  encrvis  and  T.  hrevirodris  of  authors."
Accordingly  he  only  records  T.  rigida.
They  have  always  been  favourite  Mosses  with  us,  for
nothing  can  be  more  simply  neat  than  their  smoothly
polished  and  nicely  curved  leaves,  each  tuft  crowned  with
a  seta  and  capsule.  We  should  like  much  if  some  of  om-
fair  friends  skilled  in  the  mysteries  of  wax-flower  manufac-
ture would  try  their  hand  on  a  patch  of  the  tliick-leaved
Tortula,  for  the  leaves  have  a  consistence  suited  to  make
them  subjects  of  such  an  experiment.
**  Leaves  more  or  less  memhranous.
t  Perich(Btial  leaves  convolute,  sheathing.
4.  ToKTULA  coNVOLUTA,  Sw.  [Convolute  Screw  Moss.)
Stems  rather  short;  leaves  oblongo-lanceolate,  acute,  their
margins  plane,  those  of  the  pericha^tium  remarkably  invo-
lute ;  capsule  oblong ;  lid  rostrate. — Eng.  FL  p.  44<.  Bar-
bula  convoluta.  Mull.  Si/n. pt.  I. p.  G15.
Banks,  and  on  moist  clayey  soil.  Tr.  Spring.  The  con-
volution of  the  pericha^tial  leaves  is  a  very  marked  character.
5.  Tortula  revoluta,  Brid.  [Revolute  Screw  Moss.)
Stems  short ;  leaves  lanceolate,  acute,  their  margins  remark-
ably revolute,  those  of  the  perichsetium  sheathing,  involute ;


158  HISTORY    OF    BRITISH    MOSSES.
