﻿382 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.96 
  

  

  anterior 
  edge 
  of 
  the 
  preorbital 
  bone 
  would 
  be 
  straight, 
  and 
  the 
  

   maxillary 
  and 
  premaxillary 
  with 
  nearly 
  straight 
  contour 
  would 
  extend 
  

   in 
  line 
  with 
  the 
  straight 
  preorbital 
  edge. 
  The 
  lips 
  would 
  not 
  be 
  

   specialized 
  with 
  a 
  thin 
  edge 
  or 
  with 
  modified 
  teeth 
  and 
  papillae. 
  

   Among 
  the 
  genera 
  recognized 
  herein, 
  Agonostomus 
  comes 
  nearest 
  to 
  

   fitting 
  the 
  above 
  group 
  of 
  characters 
  and 
  may 
  be 
  considered 
  as 
  nearest 
  

   the 
  ancestral 
  stock 
  of 
  the 
  family. 
  

  

  The 
  accompanying 
  figure 
  32 
  is 
  presented 
  to 
  show 
  in 
  a 
  graphic 
  

   manner 
  some 
  of 
  the 
  probable 
  structural 
  relationships 
  common 
  to 
  

   certain 
  mugiiid 
  genera. 
  Joturus 
  with 
  its 
  projecting 
  snout 
  and 
  

   broadly 
  attached 
  gill 
  membranes 
  may 
  represent 
  the 
  most 
  specialized 
  

   genus, 
  more 
  or 
  less 
  in 
  the 
  general 
  line 
  of 
  descent 
  from 
  an 
  Agonosto- 
  

   mus-like 
  mullet. 
  

  

  Rhinomugil 
  is 
  an 
  aberrant 
  genus. 
  The 
  nasal 
  openmgs 
  are 
  low 
  on 
  the 
  

   side 
  of 
  the 
  head, 
  in 
  line 
  with 
  the 
  lower 
  edge 
  of 
  the 
  orbit. 
  No 
  other 
  

   mullet 
  appears 
  to 
  be 
  closely 
  related 
  to 
  this 
  genus. 
  

  

  The 
  remaining 
  genera 
  of 
  mugiiid 
  fishes 
  appear 
  to 
  have 
  two 
  general 
  

   lines 
  of 
  specialization, 
  w^hich 
  could 
  have 
  arisen 
  from 
  a 
  mugiiid 
  stock 
  

   not 
  greatly 
  unlike 
  Mugil 
  as 
  defined 
  in 
  this 
  prelimmary 
  revision. 
  This 
  

   genus 
  has 
  the 
  straight 
  front 
  edge 
  of 
  the 
  preorbital 
  and 
  nearly 
  straight 
  

   contour 
  of 
  maxillary 
  and 
  premaxillary 
  in 
  line 
  with 
  front 
  edge 
  of 
  

   preorbital. 
  The 
  lower 
  lip 
  is 
  thin 
  but 
  unmodified. 
  The 
  first 
  line 
  of 
  

   specialization, 
  as 
  represented 
  by 
  Chelon, 
  Crenimugil, 
  and 
  Heteromugil, 
  

   has 
  a 
  concave 
  front 
  edge 
  of 
  preorbital 
  with 
  strongly 
  bent 
  premaxillary 
  

   and 
  maxillary 
  bones 
  posteriorly, 
  usually 
  exposed 
  below 
  the 
  preorbital. 
  

   The 
  lips 
  and 
  teeth 
  may 
  or 
  may 
  not 
  be 
  specialized. 
  The 
  second 
  line 
  

   of 
  specialization 
  represents 
  a 
  group 
  of 
  genera, 
  namely 
  Xenomugil, 
  

   Neomyxus, 
  Chaenomugil, 
  and 
  probably 
  Cestraeus, 
  with 
  lower 
  lips 
  

   folded 
  downward 
  with 
  higlily 
  specialized 
  teeth 
  and 
  lips. 
  The 
  extreme 
  

   specialization 
  in 
  this 
  group 
  may 
  be 
  considered 
  the 
  fresh-water 
  genus 
  

   Cestraeus. 
  This 
  genus 
  has 
  the 
  teeth 
  specialized 
  into 
  lamellae 
  on 
  the 
  

   external 
  surface 
  of 
  the 
  lower 
  jaw. 
  

  

  All 
  fresh-water 
  genera 
  of 
  mullets 
  have 
  ctenoid 
  scales 
  and 
  all 
  marine 
  

   genera 
  of 
  mullets 
  have 
  cycloid 
  scales 
  except 
  Chaenomugil, 
  which 
  has 
  

   ctenoid 
  scales. 
  

  

  Genus 
  CESTRAEUS 
  Valenciennes 
  

  

  Cestraeus 
  Valenciennes, 
  in 
  Cuvier 
  and 
  Valenciennes, 
  Histoire 
  naturelle 
  des 
  

   poissons, 
  vol. 
  11, 
  p. 
  157, 
  pi. 
  315, 
  1836 
  (genotype, 
  Cestraeus 
  plicatil's 
  Valen- 
  

   ciennes) 
  (Celebes). 
  

  

  Gonostomyxus 
  MacDonald, 
  Proc. 
  Zool. 
  See. 
  London, 
  1869, 
  No. 
  1, 
  p. 
  39, 
  pi. 
  1 
  

   (genotype, 
  Gonostomyxus 
  loa-loa 
  MacDonald) 
  (Rewa 
  River, 
  Na 
  Vita 
  Levu, 
  

   Fiji 
  Islands). 
  

  

  Aeschrichthys 
  Macleay, 
  Proc. 
  Linn. 
  Soc. 
  New 
  South 
  Wales, 
  vol. 
  8, 
  p. 
  5, 
  text 
  figs., 
  

   pi., 
  1883 
  (genotype, 
  Aeschrichthys 
  goldiei 
  Macleay) 
  (rivers 
  of 
  New 
  Guinea). 
  

  

  