Order  VIII.  ANSERES. 
Family  V.  Larid^?, 
The  third  Subfamily, 
STERNINiE,  or  Terns, 
have  the  Bill  more  or  less  lengthened,  generally  slender,  straight,  with  the  culmen  sometimes  curved  at 
the  tip,  which  is  acute ;  the  nostrils  basal,  lateral,  and  linear  ;  the  Wings  very  long  and  pointed  ;  the 
Tail  long,  and  more  or  less  forked  ;  the  Tarsi  usually  short,  and  slender ;  the  Toes  of  various  lengths, 
and  more  or  less  webbed  ;  and  the  hind  toe  long  and  slender. 
Sterna  Linn* 
Bill  more  or  less  long,  strong,  with  the  culmen  slightly  curved  to  the  tip,  which  is  acute  ;  the  gonys 
straight,  and  half  the  length  of  the  bill ;  the  nostrils  lateral,  placed  towards  the  middle  of  the  bill  and 
longitudinal,  with  the  frontal  plumes  advancing  close  to,  or  near,  the  opening  Wings  very  long  and 
pointed,  with  the  first  quill  the  longest.  Tail  more  or  less  long,  and  generally  forked.  Tarsi  more  or 
less  long  and  slender.  Toes  moderate,  the  two  outer  ones  nearly  equal,  and  the  three  anterior  ones 
united  by  an  indented  web  ;  the  hind  toe  very  short ;  the  claws  moderate,  slightly  curved,  and  acute. 
These  birds  are  scattered  throughout  both  hemispheres,  migrating  in  flocks  from  place  to  place  according  to  the 
season.  They  usually  frequent  the  coasts  or  salt  marshes,  but  are  occasionally  seen  on  the  borders  of  inland  lakes  and 
rivers.  They  are  continually  on  the  wing,  and  their  flight  is  elevated,  of  long  continuance,  and  extended  far  from 
land.  When  seeking  their  food,  they  generally  perform  large  circles,  or  hover  over  it,  and  then  suddenly  dart  straight 
upon  it.  At  other  times  they  sweep  the  surface  of  the  water,  seizing  with  their  bill  any  objects  that  may  be  floating  on 
the  sea.  They  float  with  buoyancy  on  the  surface,  but  rarely,  if  ever,  exercise  their  power  of  swimming.  The 
beach,  sand  shoals,  rocks,  and  trees  are  their  usual  resorts  when  seeking  rest.  Fish  form  their  chief  subsistence, 
though  they  also  feed  on  various  kinds  of  marine  animals,  &c.  The  large  species  sometimes  attack  the  young  and  eggs 
of  other  sea  birds.  The  eggs  are  from  two  to  four  in  number,  and  are  usually  deposited  in  a  slight  hollow  on  sand 
bars  of  insulated  rocks.  The  hatching  of  the  eggs  is  mostly  left  to  the  influence  of  the  sun,  the  parent  only  sitting  on 
them  at  night  and  during  cold  weather ;  yet  the  young  when  hatched  are  most  carefully  fed,  and  protected  from  the 
attack  of  other  birds. 
1.  S.  caspia  Pall.  Nov.  Com.  Petr.  xiv.  583.,  Zoogr.  t.  78.,  Mus.  j      3.  S.  vclox  Riipp.  Atlas,  1. 13. 
Carls,  iii.  t.  62.  —  Sterna  megarhynchus  Meyer  ;    S.  Tschegrava         4.  S.  cristata  Swains.  B.  of  W.  Afr.  ii.  247.  pi.  30. 
Gmel.  ;  Type  of  Hydroprogne  Kaup  (1829).  5.  S.  Bergii    Licht.    Cat.  Dupl.  Berl.  Mus.  p.  80.,    Griff.  An. 
2.  S.  pelecano'ides  Vigors,    King's  Nat.  Austr.  App.  p.  422.  —     Kingd.  iii.  pi.  p.  647- 
Sterna  poliocerca  Gould,  Proc.  Z.  S.  1837.  p.  26.,  Syn.  Austr.  B.  p.  6.  S.  affinis  Riipp.  Atlas,  t.  14.  —  Sterna  media  Horsf.  •  S. 
pi.  (head);    St.  caspia  \ ax.  Lath.    Phill.  Voy.  pi.  p.  77- ;    Type  of     arabica  Eltrenb. 
Pelecanopus  Wagl.  (1832).  7.  S.  cayanensis  Gmel.  PI.  enl.  988. —  Sterna  cayana  Lath. 
*  Established  by  Linnsus  in  1748  (Sy  sterna  Natures).  It  embraces  Gelochelidon  of  Brehm  (1830),  with  which  Laropis  of  Wagler  (1832) 
is  synonymous  ;  Thalasseus  of  M.  Boie  (1822),  of  which  Aetochelidon  of  M.  Kaup  (1829)  is  a  synonyme  ;  Hydroprogne  of  M.  Kaup  (1829), 
which  name  is  coequal  with  Sylochelidon  of  M.  Brehm  (1830)  and  Helopus  of  Wagler  (1832)  ;  Plunetis  of  Wagler  (1832)  ;  Thalassea  of 
M.  Kaup  (1829)  ;  Stemula  of  M.  Boie  (1822)  ;  also  Haliplana,  Onychoprion  and  Pelecanopus  of  Wagler  (1832). 
