188  MR.  W.  S.  MACLEAY  ON  THE  NATURAL  HISTORY  OF  URANIA. 
Ur.  FernandirKs  is  by  far  most  plentiful  on  the  sea-shore,  because  there  grows  its 
favourite  Omphalea.  However,  it  prefers  to  sport  about  the  leaves  of  Coccoloha  uvifera 
(unless  when  depositing  its  eggs'), — a  circumstance  which  made  me  long  search  in 
vain  for  the  larva  on  this  last-mentioned  tree.  On  the  sea-coast  of  Surinam  and 
Cayenne  grows  another  species  of  Omphalea-  {Omph.  diandra),  which  in  all  probability 
affords  pabulum  to  Ur.  Leilus,  for  I  have  remarked  that  the  minor  natural  groups  of 
Lepidoptera  often  keep  very  constant  to  the  same  natural  group  of  plants^.  Therefore, 
also,  the  splendid  Madagascar  insect  Ur.  Ripheus,  and  the  less  gaudy  Ur.  Orontes  of 
the  East  Indian  islands,  nay,  Patroclus,  and  all  the  other  species,  may  likewise  feed  on 
the  leaves  of  sea-side  Euphorbiacea.  In  his  '  Narrative  of  a  Survey  of  the  Coasts  of 
Australia'*,  Capt.  P.  P.  King,  R.N.,  describes  his  having  found  a  variety  of  Ur.  Orontes^ 
sporting  in  immense  numbers  about  a  grove  of  Pandanus  trees  at  the  mouth  of  a  stream 
which  falls  into  the  sea  near  the  extremity  of  Cape  Grafton  on  the  north-east  coast  of 
New  Holland.  But  I  have  little  doubt  that  this  species  flitted  about  the  Pandani  as 
Ur.  FernandincB  does  about  the  Coccoloha,  while  its  eggs  and  larvcB  might  have  been 
found  on  the  neighbouring  Euphorbiacea.  Ur.  Orontes,  however,  differs  in  many  essential 
respects  from  Ur.  Fernandince,  and  probably  forms  one  of  those  genera  into  which,  as  I 
perceive  from  a  note  in  the  last  edition  of  Cuvier's  '  R^gne  Animal,'  Dalman  has  distri- 
buted the  Fabrician  genus  Urania.  On  this  subject  I  can  say  no  more  at  present,  as  I 
have  not  yet  seen  his  characters  of  distinction  ;  but  I  shall  be  disappointed  if  there  be 
not  found  matter  enough  in  the  above  observations  to  be  turned  to  use  by  those  who 
are  investigating  the  natural  affinities  of  Dalman's  brilliant  group ^. 
'  Urania  agrees  with  the  generality  of  Linnsean  Papiliones  in  depositing  its  eggs  singly,  and  in  gluing  each 
egg  to  its  destined  leaf,  by  alighting  on  it  for  a  moment,  or  rather  by  touching  it  with  its  abdomen.  1  have 
rarely  seen  a  leaf  with  more  than  two  eggs  of  Urania. 
-  If  the  Jamaica  Omphalea  be  a  different  species  from  the  Cuba  plant,  Ur.  Sloanus  will  more  probably  be  a 
distinct  species  from  Ur.  Fernandinte. 
3  Thus  the  larva  of  the  Heliconida,  so  close  to  Argynnis,  devour  the  leaves  of  the  various  species  of  Passiflora, 
and  those  of  the  Euplaidce  keep  close  to  the  genus  Asclepias  of  Linnaeus.  Hence  likewise  we  learn  that  Heli- 
conia  Ricini,  a  Linnsean  species,  has  a  false  name,  as  the  larva  of  no  Heliconia  will  touch  a  Ricinus,  or  indeed 
any  plant  but  one  of  the  Passiflorea.  Hence  also  it  is  that  the  genus  Heliconia  is  peculiar  to  the  New  World. 
*  Vol.  ii.  p.  14. 
This  insect  has  also  been  described  as  Castnia  Orontes :  and  that  there  is  some  close  kind  of  relation  between 
Castnia  and  Urania,  I  have  not  the  least  doubt. 
^  This  is  not  the  place  for  a  detailed  generalization  of  the  Lepidopterous  wing,  else  I  might  show,  with  Mr.  Jones, 
that  the  nervures  of  the  wings  in  the  genus  Urania  differ  most  considerably  from  those  of  Hesperia,  and  indeed 
all  other  diurnal  Lepidoptera.  It  is  strange,  as  indeed  Messrs.  KIrby  and  Spence  have  already  noticed,  that  Lepi- 
dopterists,  complaining  so  much  as  they  do  of  the  deficiency  of  strong  characters  to  guide  them  in  the  distri- 
bution of  their  favourite  insects,  should  have  paid  so  little  attention  to  those  nervures  which,  if  traced  from  the 
.simple  form  which  the  wing  possesses  in  Pterophorus  and  Orneodes  up  to  the  complex  form  it  presents  in  Pa- 
pilio,  will  be  found,  while  steadily  varying,  to  present  most  valuable  characters.  Mr.  Jones,  in  the  '  Linnean 
Transactions',  vol.  ii.  p.  63,  first  gave  the  hint  of  applying  considerations  founded  on  the  nervures  of  the  wing. 
