THE  REV.  R.  T.  LOWE  ON  ALEPISAURUS. 
397 
the  external  angle  of  the  mouth,  or  termination  of  the  commissure.  The  teeth  in  the 
lower  jaw  do  not  extend  backwards  beyond  a  point  corresponding  nearly  with  that  in 
which  the  palatal  teeth  terminate  in  the  upper  jaw:  between  one  fourth  and  one  fifth  of 
the  whole  length  of  each  jaw,  from  the  external  termination  of  the  commissure,  is  thus 
unarmed  posteriorly. 
The  tongue  is  small,  very  narrow,  convex  in  the  middle,  smooth  and  black. 
The  branchiostegous  membrane,  in  this  third  individual,  has  seven  rays  on  each 
side. 
The  pectoral  fins  are  longer  than  the  head,  or  between  one  eighth  and  one  ninth  of 
the  entire  length.  The  ventral  fins  are  not  quite  half  the  length  of  the  pectoral  fins, 
and  more  of  a  triangular  form  ;  while  the  pectoral  fins  are  contracted  at  the  base,  with- 
out any  posterior  angle,  and  thus  are  truly  lanceolate.  The  first  ray  of  both  the  pec- 
toral and  ventral  fins  is  rough,  like  the  first  ray  of  the  first  dorsal  fin. 
The  dorsal  fin  was  so  perfect  in  the  present  specimen,  that  the  following  account 
of  it  may  be  depended  on,  so  far  as  regards  the  individual.  It  differs  considerably  in 
outline  from  the  formerly  published  figure,  being  less  arched,  or  more  straight  and 
parallel  with  the  line  of  the  back  ;  not  highest  in  the  middle,  but  towards  the  hinder 
end,  and  having  the  fourth  ray  in  front  produced  beyond  those  immediately  adjoining  ; 
the  intermediate  portion  being  nearly  horizontal,  or  very  gradually  rising  backwards. 
Its  form  is  thus  something  like  that  of  the  dorsal  fin  in  Histiophorus  Indicus,  Cuv.  & 
Val.,  as  represented  in  the  '  Histoire  Naturelle  des  Poissons'',  only  the  anterior  part  in 
this  Alepisaurus  is  much  lower.  It  consists  of  forty-four  unbranched  or  simple  inarti- 
culated  rays,  whose  points  are  certainly  not  produced  beyond  the  membrane.  The  first 
ray  is  on  a  line  with  the  first  ray  of  the  pectoral  fins,  and  rough  with  oblique  transverse 
grooves  in  front :  it  is  4  inches  long,  which  is  something  more  than  the  greatest  depth 
of  the  fish  in  any  part.  The  two  next  rays  are  longer,  each  an  inch,  than  the  preceding, 
and  smooth  or  even,  like  all  the  following.  The  fourth  ray  is  more  than  twice  the 
length  of  the  first  (9-i-  inches),  but  not  produced  beyond  the  membrane.  The  fifth  ray 
is  2  inches  shorter  than  the  fourth,  or  just  the  length  of  the  pectoral  fins  ;  and  the  ten 
or  twelve  2  next  are  nearly  the  same  length  as  the  fifth,  or  gradually  a  very  little  longer, 
proceeding  backwards.  The  following  rays  become  more  rapidly  elongated  to  the 
twenty-fourth,  which,  with  the  twenty-third,  is  about  the  same  length  as  the  fourth 
ray.  This  twenty-fourth  ray  is  at  about  two  thirds  of  the  length  of  the  whole  dorsal  fin 
from  its  origin.  The  twenty-fifth  and  twenty-sixth  rays  are  but  little  shorter  than  the 
twenty-third  or  twenty-fourth.  The  last  eighteen  rays  decrease  rapidly  in  length,  and 
slope  more  backwards  than  those  before  them :  the  last  of  all,  or  forty-fourth,  is  one 
quarter  of  the  length  of  the  first  ray,  or  one  inch  long,  and  joined  by  a  small  web 
to  the  body  at  its  base.  The  anterior  rays  are  rather  remote  ;  the  posterior,  particu- 
larly the  last  twenty,  gradually  closer  and  more  crowded.    All  the  rays  are  extremely 
'  t.  229. 
2  The  eighth  ray  in  this  Bpecimen  is  irregularly  hent  or  crooked  in  the  middle  ;  endently  the  result  of  some 
former  injury. 
VOL.  I.  .  3  G 
