43-2 
scope,  though  a  pocket  lens  will  be  needed  in  order  to  determine  the 
sculpturing  of  the  integument  and  those  other  characters  which  are 
embodied  in  the  synopsis.  It  has  not  been  possible  to  devise  a  key 
for  the  identification  of  the  various  stages  in  the  development  of  the 
young  adult  females,  as  these  vary  so  greatly  in  size  and  shape  that 
it  would  be  impossible  to  do  so  with  any  degree  of  accuracy  or  without 
entering  into  minute  microscopical  characters  which  for  the  most  part 
are  visible  only  after  careful  and  somewhat  tedious  preparation.  The 
exact  determination  of  the  closely  allied  species  of  Rhipicefhalus 
cannot,  however,  be  made  without  a  very  careful  study  of  the  minute 
anatomical  characters  by  an  expert. 
Key  to  the  Nine  Species  of  Ticks  found  in  Jamaica. 
A.  .Scutum  or  shield  absent.  Sexes  similar.  Distension  after  feeding 
slight  in  both  sexes. 
T .  Colour  chocolate  brown  ;  body  flat ;  skin  with  numerous 
oval  and  round  discs  -  -  Argas  persicus  (p.  434). 
B.  Scutum  present.  Sexes  dissimilar.  Distension  after  feeding 
great  in  female,  very  slight  in  male. 
Male 
Upper  surface  yellowish  brown,  reddish  brown  or  pitchy 
brown. 
2.  Mouth  parts  angulate  at  sides ;  ventral  surface  behind  the 
anus  without  a  median  furrow 
Mar garopus  anniilatus  australis  (p.  435). 
3.  Mouth  parts  similar  to  2  ;  ventral  surface  behind  anus  with 
a  well-defined  median  furrow ;  scutum  covered  with  fine 
but  well  separated  punctations  - 
Rhipicephalus  bursa. 
4.  Mouth  parts  similar  to  2  ;  ventral  furrow  as  in  3,  scutum 
with  large  and  small  punctations  distributed  regularly 
over  the  whole  surface  - 
Rhipicephalus  sanguineus  (p-437)- 
3.  Mouth  parts  not  angulate  at  sides  ;  scutum  pitchy  black, 
with  a  median  row  of  punctations  on  posterior  half 
Dermacentor  nitens  (p.  43Q). 
