STERiXIN^.. 
buoyant,  and  performed  in  rapid  and  sudden  evolutions,  particularly  when  darting  after  their  food,  which  consists 
almost  entirely  of  various  kinds  of  insects,  especially  those  of  the  neuropterous  order.  They  occasionally,  however, 
attack  the  fry  of  fish  and  aquatic  worms.  The  nest  is  generally  formed  in  a tuft  of  flags  or  broad  grass,  just  elevated 
above  the  surface  of  the  water ; and  sometimes  it  is  placed  on  the  floating  leaves  of  water  plants.  The  eggs  are  usually 
from  two  to  four  in  number. 
1.  hyhrida  (Pall.)  Zoogr.  ii.  p.  338.  — Sterna  leucopareia 
Temm.  Gould,  B.  of  Eur.  pi.  424. 
2.  H.  albostrlata  G.  R.  Gray,  Zool.  Ereb.  and  Terr.  Birds,  pi.  21., 
Ellis’s  Icon.  ined.  (1776)  54. 
3.  H.  nigra  (Linn.)  PI.  enl.  333.  — Sterna  leucoptera  Temm.  ; 
S,  fissipes  Pall. ; S.  nsevia  Linn.  PI.  enl.  924. ; Rallus  lariformis 
Linn.  } Gould,  B.  of  Eur.  pi.  422. 
4.  H.  plumbea  (Wils.)  Amer.  Orn.  pi.  60.  f.  3.  — Sterna  nigra 
Linn.  ; S.  obscura  Lath. 
5.  H.^fixsipes  (Linn.)  Pi.  enl.  924.  — Sterna  na?via  et  S.  nigra 
Briss. 
PHiETUSA  Wagl.*^ 
Bill  large,  strong,  longer  than  the  head,  with  the  culmen  and  lateral  margins  curved  to  the  tip,  which 
is  acute ; the  gonys  less  than  the  length  of  the  lower  mandible,  straight  and  angulated ; the  nostrils 
lateral,  ovate,  placed  towards  the  middle  of  the  bill.  Wings  long,  with  the  first  quill  the  longest.  Tail 
rather  short,  and  strongly  emarginated.  Tarsi  nearly  as  long  as  the  outer  toe.  Toes  short,  the  two 
outer  ones  nearly  equal  and  longest,  the  inner  one  very  short,  and  all  united  by  an  indented  web  ; the 
hind  toe  long  and  slender  ; the  claws  long,  curved,  and  rather  depressed. 
The  species  are  found  on  the  coasts  of  the  tropical  parts  of  America  and  Africa. 
1.  P.  magnirostris  (Licht.)  Wagl.  Cat.  Dupl.  Berl.  Mus.  p.  81.,  I 2.  P.  ? galericnlata  (Lieht.)  Cat.  Dupl.  Berl.  Mus.  p.  81. 
Spix,  Av.  Bras.  t.  104.,  Azara  No.  41.8,  414 Sterna  brevirostra  3.  P.  (.?)  jwclanoO's  Swains.  B.  of  W.  Afr.  ii.  p.2.52. 
Pieill.  I 
O.  H.  ^risca  (Horsf.)  Linn.  Trans,  xni.  p.  199. 
7.  H.  melanogaster  (Temm.)  PI.  enl.  434.  — Sterna  acuticauda 
Gray,  111.  Ind.  Zool.  pi.  70.  f.  3. 
8.  H.  fluviatilis  Gould,  Proc.  Z.  S.  1842.  p.  140. 
9-  H.  similis  (Gray),  111.  Ind.  Zool.  pi.  70.  f.  2. 
10.  Yi.  javanioa  (Horsf.)  Linn.  Trans,  xiii.  p.  198.,  Gray,  111. 
Ind.  Zool.  pi.  70.  f.  1 . 
11.  H.  indica  (Steph.)  Gen.  Zool.  xiii.  I69. 
Gygis  Wagl.f 
Bill  longer  than  the  head,  with  the  culmen  and  lateral  margins  nearly  straight  to  the  tip,  which  is  acute ; 
the  gonys  two  thirds  the  length  of  the  lower  mandible,  and  angulated ; the  nostrils  lateral,  placed  near 
the  base,  and  longitudinal.  Wings  long,  -with  the  first  quill  the  longest.  Tail  long,  and  strongly 
emarginated.  Tarsi  very  short  and  strong.  Toes  long,  the  two  outer  nearly  equal,  and  longer  than 
the  inner  one,  and  all  united  by  a strongly  indented  web ; the  hind  toe  very  long  and  slender ; the 
elaws  moderate  and  much  curved. 
This  type  is  found  in  the  neighbourhood  of  various  islands  of  the  South  Seas. 
G.  Candida  (Forst.)  Wagl.  Desc.  Anim.p.  179* — Sterna  alba  | ined.  S3.,  Ellis’s  Icon.  ined.  56. 
^parr.  Mus.  Carls,  i.  t.  11.,  Portlock’s  Voy.  pi.  p.  312.,  Banks,  Icon.  1 
* Established  by  Wagler  in  1832  (/sis,  p.  1224.).  Thalassites  of  Mr.  Swainson  (1837)  is  coequal, 
t Wagler  established  this  genus  in  1832  {Isis,  p.  1223.). 
