I. A  KIN  1 
l.  X.  Sabini  Leuh,  Lin.  Trans,  xii.  520.  pi.  20.,  Wils.  111.  of  Zool. 
pL  8.  i —  Xema  collaris  I.cach,  J»rd.  and  Selby,  111.  Orn.  n.  s.  pi,  35., 
Audub.  B.  of  Amer.  pi.  288.,  Gould,  B.  of  Bur.  pi.  429. 
o  > 
—  Moucttc  a  queue  fourchue,  "Ntbotue,  Rev.  Zool. 
i  s  K).  290. 
Hissa  Leach* 
Bill  Longer  than  the  head,  strong,  and  laterally  compressed,  with  the  eulmen  straight  at  the  base,  and 
curved  from  the  nostrils  to  the  tip ;  the  gonys  short  and  advancing  upwards ;  the  nostrils  lateral,  basal, 
and  tlic  opening  longitudinal.  Wimjx  lengthened  and  pointed,  with  the  first  qnill  the  longest.  Tail 
moderate  and  even.  Tarsi  much  shorter  than  the  middle  toe,  strong,  and  covered  in  front  with 
transverse  scales.  Toes  very  long,  slender,  and  united  together  by  a  full  membrane;  the  hind  toe 
rudimental  and  elevated. 
It  is  in  the  northern  parts  of  the  old  and  new  continents  that  these  birds  are  generally  seen  in  flocks  on  the  wing, 
floating  gracefully,  high  in  the  air,  and  sweeping  in  extended  circles.  They  are  capable  of  flying  against  the  heaviest 
gale,  passing  close  over  the  top  of  each  succeeding  wave  ;  and  every  now  and  then  descend  with  a  spiral  curve  towards 
the  water,  supporting  themselves  by  quick  motions  of  the  wings,  until  they  dart  at  a  young  herring  or  some  bit  of  offal, 
which  having  secured  they  fly  away,  probably  chased  by  some  other  species  anxious  to  rob  them  of  the  prize.  These 
enemies  frequently  force  them  to  disgorge  the  food  which  they  have  just  swallowed.  From  the  shortness  of  their  legs 
they  are  most  awkward  in  walking  on  the  land,  but,  in  the  air  or  on  the  water,  few  birds  surpass  them  in  ease  and 
activity  of  movements.  The  nests  are  found  on  the  narrow  projections  of  the  rocks,  so  small  as  barely  to  admit  their 
breadth.    They  are  composed  of  sea  weeds  and  coarse  grass;  and  the  eggs  are  three  in  number. 
1.  R .  tridactyla  (Lath.)  Leach,  PI.  enl.  253.  387. —  Rissa 
Brunnichii  Leach,  Gould,  B.  of  Eur.  pi.  435.,  Audub.  B.  of  Amer, 
pi.  224. ;  Lams  torquatus,  L.  gavia,  et  L.  canus  Pall. 
2.  R.  nivea  (Pall.)  Zoogr.  ii.  320.  t.  76. —  Larus  brachyrhyn- 
chus  Gould,  Voy.  Sulphur,  Birds,  pi.  34. 
Pagophila  Kanp.-f 
Hill  rather  strong,  straight,  and  compressed,  with  the  basal  portion  of  the  eulmen  straight,  and  the 
apical  part  curved  to  the  tip;  the  gonys  much  angulated  beneath,  and  advancing  upwards;  the  nostrils 
lateral,  basal,  and  longitudinal.  Wings  lengthened  and  pointed,  with  the  first  quill  the  longest.  Tail 
moderate  and  even.  Tarsi  shorter  than  the  middle  toe,  strong,  and  covered  with  transverse  scales.  Toes 
strong,  the  lateral  ones  unequal,  the  anterior  ones  united  by  an  indented  web  ;  the  hind  toe  short  and 
elevated. 
The  type  of  this  division  is  peculiar  to  the  very  high  northern  latitudes  of  both  continents,  and  is  usually  seen  out  at 
sea,  following  in  the  wake  of  the  whalc-flshers,  as  its  food  consists  of  the  blubber  or  flesh  of  dead  whales.  The  eggs  are 
deposited  upon  the  rocks  and  high  broken  cliffs  that  overhang  the  sea. 
V.  eburnea  (Gmel.)  Kaup,  PI.  enl.  004. — Larus  niveus  Marl.  ;  L.  candidus  Fair.  Gould,  B.  of  Eur.  pi.  436.,  Audub.  B.  of  Amer.  pi.  237. 
*  Dr.  Leach  established  this  genus  prior  to  1825,  when  it  was  adopted  by  Mr.  Stephens  (Gen.  Zool.  xiii.  p.  180.).  Cheimonea  of 
M.  Kaup  (182*))  was  founded  on  the  same  type. 
+  This  division  was  originally  established  under  the  name  of  Gavia  by  Boie  in  1822  ;  but,  as  that  word  had  been  previously  employed,  I 
have  adopted  the  above  name,  which  was  proposed  by  M.  Kaup  in  1829.     In  1842  Mr.  Macgillivray  used  Catosparactes  for  the  same  type. 
Augutt,  1845. 
