organization　of　the　internal　parts。　　The　mouth；　surrounded　by
  tentacles；　leads　by　gullet　and　gizzard　through　a　channel　into　a
  digesting　stomach；　from　which　the　rejectable　matter　passes　upwards
  through　an　intestinal　canal　till　it　is　discharged　near　the　mouth。
  The　tentacles　also　differ　much　from　those　of　true　Polypes。　　Instead
  of　being　fleshy　and　contractile；　they　are　rather　stiff；　resembling
  spun　glass；　set　on　the　sides　with　vibrating　cilia；　which　by　their
  motion　up　one　side　and　down　the　other　of　each　tentacle；　produce　a
  current　which　impels　their　living　food　into　the　mouth。　　When　these
  tentacles　are　withdrawn；　they　are　gathered　up　in　a　bundle；　like　the
  stays　of　an　umbrella。　　Our　Plate　I。　contains　the　following　examples
  of　Polyzoa。
  VALKERIA　CUSCUTA。　PL。　I。　FIG。　3。
  From　a　group　in　one　of　Mr。　Lloyd's　vases。　　Fig。　3　A　is　the　natural
  size　of　the　central　group　of　cells；　in　a　specimen　coiled　round　a
  thread…like　weed。　　Underneath　this　is　the　same　portion　enlarged。
  When　magnified　to　this　apparent　size；　the　cells　could　be　seen　in
  different　states；　some　closed；　and　others　with　their　bodies
  protruded。　　When　magnified　to　3　D；　we　could　pleasantly　watch　the
  gradual　eversion　of　the　membrane；　then　the　points　of　the　tentacles
  slowly　appearing；　and　then；　when　fully　protruded；　suddenly
  expanding　into　a　bell…shaped　circle。　　This　was　their　usual
  appearance；　but　sometimes　they　could　be　noticed　bending　inwards；　as
  in　fig。　3　C；　as　if　to　imprison　some　living　atom　of　importance。
  Fig。　B　represents　two　tentacles；　showing　the　direction　in　which　the
  cilia　vibrate。
  CRISIA　DENTICULATA。　　PL。　I。　FIG。　4。
  I　have　only　drawn　the　cells　from　a　prepared　specimen。　　The　polypes
  are　like　those　described　above。
  GEMELLARIA　LORICATA。　　PL。　I。　FIG。　5。
  Here　the　cells　are　placed　in　pairs；　back　to　back。　　5　A　is　a　very
  small　portion　on　the　natural　scale。
  CELLULARIA　CILIATA。　　Pl。　I。　FIG。　7
  The　cells　are　alternate　on　the　stem；　and　are　curiously　armed　with
  long　whip…like　cilia　or　spines。　　On　the　back　of　some　of　the　cells
  is　a　very　strange　appendage；　the　use　of　which　is　not　with　certainty
  ascertained。　　It　is　a　minute　body；　slightly　resembling　a　vulture's
  head；　with　a　movable　lower　beak。　　The　whole　head　keeps　up　a　nodding
  motion；　and　the　movable　beak　occasionally　opens　widely；　and　then
  suddenly　snaps　to　with　a　jerk。　　It　has　been　seen　to　hold　an
  animalcule　between　its　jaws　till　the　latter　has　died；　but　it　has　no
  power　to　communicate　the　prey　to　the　polype　in　its　cell　or　to
  swallow　and　digest　it　on　its　own　account。　　It　is　certainly　not　an
  independent　parasite；　as　has　been　supposed；　and　yet　its　purpose　in
  the　animal　economy　is　a　mystery。　　Mr。　Gosse　conjectures　that　its
  use　may　be；　by　holding　animalcules　till　they　die　and　decay；　to
  attract　by　their　putrescence　crowds　of　other　animalcules；　which　may
  thus　be　drawn　within　the　influence　of　the　polype's　ciliated
  tentacles。　　Fig。　7　B　shows　the　form　of　one　of　these　〃birds'　heads；〃
  and　fig。　7　C；　its　position　on　the　cell。
  FLUSTRA　LINEATA。　　PL。　I。　FIG。　1。
  In　Flustrae；　the　cells　are　placed　side　by　side　on　an　expanded
  membrane。　　Fig。　1　represents　the　general　appearance　of　a　species
  which　at　least　resembles　F。　lineata　as　figured　in　Johnston's　work。
  It　is　spread　upon　a　Fucus。　　Fig。　A　is　an　enlarged　view　of　the
  cells。
  FLUSTRA　FOLIACEA。　　PL。　I。　FIG。　2。
  We　figure　a　frond　or　two　of　the　common　species；　which　has　cells　on
  both　sides。　　It　is　rarely　that　the　polypes　can　be　seen　in　a　state
  of　expansion。
  SERIALARIA　LENDIGERA。　　PL。　I。　fig。　10。
  NOTAMIA　BURSARIA。　　PL。　　I。　fig。　11。
  The　〃tobacco…pipe〃〃　appendages；　fig。　11　B；　are　of　unknown　use：
  they　are　probably　analogous　to　the　birds'　heads　in　the　Cellularae。
  PLATE　V。
  CORALS　AND　SEA　ANEMONES。
  CARYOPHYLLAEA　SMITHII。　　PL。　V。　FIG。　2。　　PL。　VI。　FIG。　3。
  THE　connection　between　Brainstones；　Mushroom　Corals；　and　other
  Madrepores　abounding　on　Polynesian　reefs；　and　the　〃Sea　Anemones；〃
  which　have　lately　become　so　familiar　to　us　all；　can　be　seen　by
  comparing　our　comparatively　insignificant　C。　Smithii　with　our
  commonest　species　of　Actinia　and　Sagartia。　　The　former　is　a
  beautiful　object　when　the　fleshy　part　and　tentacles　are　wholly　or
  partially　expanded。　　Like　Actinia；　it　has　a　membranous　covering；　a
  simple　sac…like　stomach；　a　central　mouth；　a　disk　surrounded　by
  contractile　and　adhesive　tentacles。　　Unlike　Actinia；　it　is　fixed　to
  submarine　bodies；　to　which　it　is　glued　in　very　early　life；　and
  cannot　change　its　place。　　Unlike　Actinia；　its　body　is　supported　by
  a　stony　skeleton　of　calcareous　plates　arranged　edgewise　so　as　to
  radiate　from　the　centre。　　But　as　we　find　some　Molluscs　furnished
  with　a　shell；　and　others　even　of　the　same　character　and　habits
  without　one；　so　we　find　that　in　spite　of　this　seemingly　important
  difference；　the　animals　are　very　similar　in　their　nature。　　Since
  the　introduction　of　glass　tanks　we　have　opportunities　of　seeing
  anemones　crawling　up　the　sides；　so　as　to　exhibit　their　entire　basal
  disk；　and　then　we　may　observe　lightly　coloured　lines　of　a　less
  transparent　substance　than　the　interstices；　radiating　from　the
  margin　to　the　centre；　some　short；　others　reaching　the　entire
  distance；　and　arranged　in　exactly　the　same　manner　as　the　plates　of
  Caryophyllaea。　　These　are　doubtless　flexible　walls　of　compartments
  dividing　the　fleshy　parts　of　the　softer　animals；　and　corresponding
  with　the　septa　of　the　coral。　　Fig。　2　A　represents　a　section　of　the
  latter；　to　be　compared　with　the　basal　disk　of　Sagartia。
  SAGARTIA　ANGUICOMA。　　PL。　V。　FIG。　3；　A；　B。
  This　genus　has　been　separated　from　Actinia　on　account　of　its　habit
  of　throwing　out　threads　when　irritated。　　Although　my　specimens
  often　assumed　the　form　represented　in　fig。　3；　Mr。　Lloyd　informs　me
  that　it　must　have　arisen　from　unhealthiness　of　condition；　its　usual
  habit　being　to　contract　into　a　more　flattened　form。　　When　fully
  expanded；　its　transparent　and　lengthened　tentacles　present　a
  beautiful　appearance。　　Fig。　3　A；　showing　a　basal　disk；　is　given　for
  the　purpose　already　described。
  BALANOPHYLLAEA　REGIA。　　PL。　V。　FIG。　1。
  Another　species　of　British　madrepore；　found　by　Mr。　Gosse　at
  Ilfracombe；　and　by　Mr。　Kingsley　at　Lundy　Island。　　It　is　smaller
  than　O。　Smithii；　of　a　very　bright　colour；　and　always　covers　the
  upper　part　of　its　bony　skeleton；　in　which　the　plates　are
  differently　arranged　from　those　of　the　smaller　species。　　Fig。　1
  shows　the　tentacles　expanded　in　an　unusual　degree；　1　A；　animal
  contracted；　1　B；　the　coral；　1　C；　a　tentacle　enlarged。
  PLATE　VI。
  CORALS　AND　SEA　ANEMONES。
  ACTINIA　MESEMBRYANTHEMUM。　　PL。　VI。　FIG。　1　A。
  This　common　species　is　more　frequently　met　with　than　many　others；
  because　it　prefers　shallow　water；　and　often　lives　high　up　among
  rocks　which　are　only　covered　by　the　sea　at　very　high　tide；　so　that
  the　creature　can；　if　it　will；　spend　but　a　short　portion　of　its　time
  immersed。　　When　uncovered　by　the　tide；　it　gathers　up　its　leathery
  tunic；　and　presents　the　appearance　of　fig。　1　A。　　When　under　water
  it　may　often　be　seen　expanding　its　flower…like　disk　and　moving　its
  feelers　in　search　of　food。　　These　feelers　have　a　certain　power　of
  adhesion；　and　any　not　too　vigorous　animals　which　they　touch　are
  easily　drawn　towards　the　centre　and　swallowed。　　Around　the　margin
  of　the　tunic　are　seen　peeping　out　between　the　tentacles　certain
  bright　blue　globules　looking　very　like　eyes；　but　whose　purpose　is
  not　exactly　ascertained。　　Fig。　1　represents　the　disk　only　partially
  expanded。
  BUNODES　CRASSICORNIS。　　PL。　VI。　FIG。　2。
  This　genus　of　Actinioid　zoophytes　is　distinguished　from　Actinia
  proper　by　the　tubercles　or　warts　which　stud　the　outer　covering　of
  the　animal。　　In　B。　gemmacea　these　warts　are　arranged　symmetrically；
  so　as　to　give　a　peculiarly　jewelled　appearance　to　the　body。　　Being
  of　a　large　size；　the　tentacles　of　B。　crassicornis　exhibit　in　great
  perfection　the　adhesive　powers　produced　by　the　nettling　threads
  which　proceed　from　them。
  CARYOPHYLLAEA　SMITHII。　　PL。　VI。　FIG。　3。
  This　figure　is　to　show　a　whiter　variety；　with　the　flesh　and
  tentacles　fully　expanded
  PLATE　VIII。
  MOLLUSCA。
  NASSA　RETICULATA。　　PL。　VIII。　fig。　2；　A；　B；　C；　D；　E；　F
  A　VERY　active　Mollusc；　given　here　chiefly　on　account　of　the
  opportunity　afforded　by　the　birth　of　young　fry　in　Mr。　Lloyd's
  tanks。　　The　NASSA　feeds　on　small　animalcules；　for　which；　in
  aquaria；　it　may　be　seen　routing　among　the　sand　and　stones；
  sometimes　burying　itself　among　them　so　as　only　to　show　its　caudal
  tube　moving　along　between　them。　　A　pair　of　Nassae　in　Mr。　Lloyd's
  collection；　deposited；　on　the　5th　of　April；　about　fifty　capsules　or
  bags　of　eggs　u