Order  VIIT.  ANSERES. 
Eamily  V.  Lakid^e, 
The  second  Subfamily, 
RHYNCHOPINiE,  or  Skimmers, 
have  the  mandibles  unequal,  the  upper  one  always  shorter  than  the  lower,  which  is  only  received  in  a 
narrow  groove,  their  sides  suddenly  much  compressed  from  the  base  ; the  Wings  lengthened,  acute,  and 
curved  at  the  tip ; the  Tail  moderate  and  forked ; the  Tarsi  rather  longer  than  the  middle  toe,  and 
covered  Avith  transverse  scales ; the  Toes  moderate,  and  the  anterior  partly  united  by  an  indented  web. 
Rhynchops  Linn.* 
Bill  broad  at  the  base,  but  suddenly  compressed  from  thence  to  the  tips  ; the  upper  mandible  much 
shorter  than  the  lower,  and  slightly  curved  to  the  tip,  which  is  acute,  and  grooved  beneath  to  receive  the 
edge  of  the  lower  mandible,  which  is  compressed  and  truncated ; the  nostrils  basal,  lateral,  oblong,  and 
pervious.  Wings  very  long,  and  curved  towards  the  tip,  with  the  first  quill  the  longest.  Tail  moderate 
and  forked.  Tarsi  rather  longer  than  the  middle  toe.  Toes  moderate,  with  the  lateral  ones  unequal,  and 
united  to  the  middle  toe  by  an  indented  web;  the  hind  toe  elevated,  and  touching  the  ground  with  its 
tip ; the  claws  long,  curved,  and  acute. 
The  tropical  parts  of  both  hemispheres  are  peculiarly  frequented  by  these  birds.  They  prefer  the  sheltered  inlets  and 
estuaries  of  the  rivers,  over  the  smooth  water  of  which  they  are  observed  near  the  shores  at  the  flood  tide,  seeking  their 
usual  food  of  small  fish  and  molluscous  animals.  These  they  obtain  by  slowly  ploughing  along  the  yielding  surface 
e the  prolific  sea  with  the  lower  mandible,  while  the  upper  is  elevated  out  of  the  water,  until  the  former 
touches  some  object  that  forms  a portion  of  their  food,  when  the  two  mandibles  close  together  upon  it  with  great 
rapidity.  Their  flight  is  swift  and  undulating ; when  on  the  ground  they  walk  very  awkwardly,  and,  though  they 
possess  webbed  feet,  they  rarely  swim  or  even  float  on  the  surface  of  the  water.  They  seek  repose  on  the°strand, 
or  in  the  neighbouring  marshes,  but  they  rest  during  the  day  in  flocks  on  the  isolated  shoals  left  bare  by  the  recess  of 
the  tide.  They  visit  the  low  sand  bars  and  dry  flats  of  the  coast,  for  the  purpose  of  scratching  out  a slight  hollow  in  the 
sands,  wherein  the  female  deposits  usually  three  eggs.  The  female  only  sits  on  the  nest  during  the  night,  or  in  wet  and 
stormy  weather.  The  young  are  scarcely  distinguishable  from  the  sand,  in  consequence  of  the  similarity  of  their  colour, 
^d  during  this  period  may  often  be  seen  basking  In  the  sun,  and  spreading  out  their  wings  upon  the  warm  beach, 
■the  parent  migrates  to  the  south,  as  soon  as  the  young  are  capable  of  the  voyage. 
1-  R.  nigra  Linn.  PI.  enl.  3S7.,  Wils.  Araer.  Orn.  pi.  flO.  f.  4.  — 
tynchops  borealis  Swains. ; R.  fulva  Gmol. ; R.  cinerascens  et  R. 
wevirostris  Spix,  A v.  Bras.  1. 102,  103. 
2.  R.  melanura  Swains.  Two  Cent,  and  a Quart,  p.  340. 
3.  R.  aibicollis  Swains.  Two  Cent,  and  a Quart,  p 341. 
4.  R.  alhirostris  Licht.  Cat.  Dupl.  Berl.  Mus.p.  80. — Rhynchops 
flavirostris  rieill.  Gal.  des  Ois.  t.  201.  ; R.  orientalis  Atlas, 
t.24. 
Established  in  1756  by  Linnaeus  ( Sy sterna  Natures'). 
In  1760  Brisson  proposed  Rhynchopsalia  for  the  same  set  of  birds. 
September,  1845. 
