Vol.  49.] 
DIXOSAURIAH  TEETH  F1LQM  AYLESBURY. 
567 
Tig 
!. — Inner  View 
of  Crown  of  a  Tooth 
of  ?  Pelorosaurus 
Conybeari.  ( From 
the  Weal  den  of 
Kent.) 
to  Ornithopsis ,  but  was  subsequently  considered  to  belong 
more  probably  to  Pelorosaurus  Conybeari f  although  some  of  the 
teeth  of  that  animal  must  doubtless  have 
been  of  larger  size.  This  second  tooth, 
of  which  the  figure  is  reproduced  from 
Quart.  Journ.  Geol.  Soc.  vol.  xlv.  p.  243, 
fig.  7,  differs  from  that  of  Hoplosaurus 
in  being  decidedly  broader,  and  also  by 
the  smaller  degree  of  concavity  of  its  inner 
surface ;  although  unfortunately,  from  its 
worn  condition,  its  full  height  cannot  be 
ascertained. 
Of  the  new  teeth,  the  larger  one,  which  is 
represented  in  fig.  3,  comprises  the  crown  and 
a  fragment  of  the  root,  and  is  very  similar 
to  the  specimen  assigned  to  Pelorosaurus 
Conybeari ,  although  of  somewhat  superior 
dimensions.  It  has  been  considerably  worn, 
and  the  summit  is  slightly  imperfect.  The 
iuner  surface,  on  which  the  enamel  is  ex¬ 
tremely  rugose,  entirely  lacks  the  deep, 
spoon-like  hollow  of  the  tooth  of  Hoplo- 
saurus ,  and  is  but  slightly  concave,  with 
a  broad  vertical  ridge  traversing  its  median 
line.  Externally  there  is  a  very  broad 
[Natural  size.] 
Fig.  3.  —Inner  and  Outer  Views  of  Crown  of  Tooth  of  Pelorosaurus 
humerocristatus.  ( From  the  Portlandian  of  Aylesbury .) 
[Natural  size.] 
vertical  ridge,  somewhat  curved,  and  placed  nearer  one  edge 
than  the  other.  On  the  one  side  this  ridge  is  marked  off  by  a 
Op.  cit.  p.  240. 
1 
