MR.  R.  OWEN  ON  THE  ANATOMY  OF  THE  CALYPTR^IDiE.  211 
PLATE  XXX. 
Fig.  1 .  Outside  view  of  the  shell  of  Calyptraa  Byronensis,  Gray. 
2.  Inside  view  of  the  same  shell. 
a.  The  front  part  of  the  shell,  corresponding  to  the  head  of  the  animal. 
h.  The  internal  cup. 
3.  The  soft  parts  of  the  same  species  from  the  ventral  aspect. 
4.  The  soft  parts  of  the  same  species  from  the  dorsal  aspect. 
5.  The  soft  parts  of  a  female  specimen  of  the  same  species  from  the  ventral 
aspect,  with  the  head  turned  down  to  show  the  orifice  of  the  branchial 
chamber  and  the  terminations  of  the  rectum  and  oviduct. 
6.  The  soft  parts  of  a  male  specimen  of  the  same  species  dissected  from  the 
dorsal  aspect. 
7.  The  principal  ganglia  of  the  nervous  system.    (A  bristle  is  passed  through 
the  oesophagus.) 
The  same  letters  are  used  for  the  same  parts  in  each  figure. 
a.  The  mouth. 
h.  The  tentacles.  - 
6*.  The  eyes. 
c.  (Fig.  6.)  The  penis. 
d.  The  aliform  expansions  of  the  neck. 
e.  The  anterior  expansions  of  the  foot. 
/.  The  foot. 
The  apex  of  the  foot  lodged  in  the  cavity  of  the  cup. 
/**.  The  point  of  attachment  to  the  shell. 
g.  The  mantle. 
h.  The  entry,  or  beginning,         h'.  the  end,  of  the  branchial  chamber. 
i.  The  branchial  filaments. 
k.  The  tongue  supporting  the  horny  rasp. 
I,  I.  The  salivary  glands, 
m.  The  oesophagus, 
n.  The  stomach. 
0.  The  intestine. 
p.  The  anus, 
q.  The  liver. 
r.  The  testis. 
VOL.  I.  2  F 
