﻿26 
  [Assembly 
  

  

  (Eeing 
  under 
  the 
  impression 
  that 
  the 
  following 
  spe- 
  

   cies 
  is 
  new, 
  a 
  description 
  has 
  been 
  prepared, 
  which 
  is 
  

   here 
  offered. 
  Since 
  it 
  was 
  written, 
  opportunities 
  have 
  

   occurred 
  for 
  examining 
  numerous 
  specimens 
  at 
  various 
  

   stages 
  of 
  growth, 
  and 
  no 
  marked 
  difference 
  was 
  noted 
  

   between 
  the 
  young 
  and 
  the 
  full 
  grown.) 
  

  

  PiMELODUS 
  GRACILIS, 
  (UCW 
  Sp.) 
  

  

  Characteristics. 
  — 
  Caudal 
  fin, 
  furcate; 
  body, 
  slender 
  j 
  

   mouth 
  small 
  and 
  armed 
  with 
  two 
  bands 
  of 
  minute 
  vil- 
  

   lose 
  teeth. 
  Length 
  nine 
  to 
  fifteen 
  inches. 
  

  

  Description. 
  — 
  Color, 
  dark 
  olive 
  brown 
  above 
  and 
  light 
  

   ash-colored 
  beneath 
  the 
  sides, 
  presenting 
  intermediate 
  

   shades. 
  Surface, 
  scaleless 
  and 
  smooth, 
  except 
  upon 
  the 
  

   head, 
  where 
  it 
  is 
  minutely 
  granular. 
  Lateral 
  line 
  dis- 
  

   tinct 
  and 
  nearly 
  straight. 
  Head 
  slightly 
  flattened, 
  with 
  

   a 
  longitudinal 
  depression, 
  extending 
  from 
  a 
  little 
  before 
  

   the 
  orbits 
  to 
  a 
  point 
  above 
  the 
  extremities 
  of 
  the 
  gills. 
  

   Barbels 
  eight; 
  two 
  of 
  which 
  are 
  small, 
  erectile, 
  and 
  

   placed 
  on 
  the 
  anterior 
  margin 
  of 
  the 
  posterior 
  nostrils 
  

   and 
  reaching 
  the 
  orbits. 
  Anterior 
  nostrils 
  slightly 
  tu- 
  

   bular 
  and 
  much 
  depressed. 
  The 
  angles 
  of 
  the 
  mouth 
  

   furnished 
  with 
  flattened 
  and 
  pointed 
  barbels 
  extending 
  

   back 
  to 
  the 
  tips 
  of 
  the 
  gills 
  and 
  with 
  a 
  slight 
  rudiment 
  

   of 
  an 
  accessary 
  bone 
  at 
  their 
  base. 
  Four 
  barbels 
  on 
  the 
  

   lower 
  lip, 
  tlie 
  external 
  ones 
  longest, 
  somewhat 
  flatten- 
  

   ed 
  : 
  the 
  interval 
  between 
  the 
  inner 
  ones 
  much 
  greater 
  

   than 
  between 
  those 
  on 
  the 
  same 
  side. 
  Mouth 
  small 
  

   with 
  minute 
  teeth 
  in 
  each 
  jaw 
  and 
  in 
  the 
  throat. 
  Eyes 
  

   slightly 
  prominent 
  and 
  color 
  of 
  the 
  iris 
  dusky, 
  with 
  a 
  

   narrow 
  golden 
  margin. 
  Dorsal 
  fin 
  with 
  one 
  spinous 
  

   ray 
  slightly 
  serrated 
  behind 
  and 
  six 
  branched 
  rays, 
  the 
  

   first 
  of 
  which 
  is 
  longest 
  and 
  the 
  last 
  sometimes 
  rudi- 
  

   mentary. 
  Pectoral 
  fins 
  with 
  one 
  strong 
  spinous 
  ray 
  

   sharply 
  serrated 
  behind 
  and 
  nine 
  branched 
  rays 
  which 
  

   regularly 
  diminish 
  in 
  length 
  from 
  the 
  first 
  to 
  the 
  last. 
  

   The 
  tips 
  of 
  the 
  pectorals 
  when 
  depressed 
  extend 
  beyond 
  

   the 
  middle 
  of 
  the 
  dorsal, 
  and 
  the 
  spinous 
  rays 
  of 
  these 
  

   admit 
  of 
  being 
  fixed 
  at 
  the 
  will 
  of 
  the 
  animal, 
  when 
  

   they 
  might 
  serve 
  as 
  weapons 
  for 
  defence. 
  Ventral 
  fins 
  

  

  