Glossary

away from the apex of the shell.

towards the apex of the shell.

at the apex.

(adj.) living on the bed of the sea, river, lake etc.

divided into two parts by a cleft.

(of gill plume) twofold branching; boughs and branches, but no subsequent twigs; in one plane like a feather.

fleshy excrescence like neck wattle on turkey.

shovel-like layer covering front part of philinid sea slugs.

(singular) lobe on sides or back of aeolids and some other sea slugs.

(plural) lobes on sides and back of aeolids and some other sea slugs.

semitransparent flexible horny material.

(adj.) made of chitin.

tiny elastic pigment spots which can cause rapid change to body colour by expansion /contraction.

mobile linear extensions of membrane used in feeding or locomotion.

hydroids, jellyfish, sea anemones etc.

storage capsules for unexploded cnidaria stings at tips of cerata.

horny material used to make outer layer of operculum.

the same colour as.

strong rib running across a whorl of a gastropod shell.

strong ribs running across a whorl of a gastropod shell.

(pl.) comb-like molluscan gills; usually an axis with a row of filaments either side.

comb-like molluscan gill; usually an axis with a row of filaments either side.

shaped like a finger.

away from centre of body or point of attachment.

a sea slug in the infraorder Doridacea; with gills and rhinophores on the dorsum; often shaped like half a lemon or grape.

special form of drifting larva with an inner and outer shell, the intervening space filled with sea water.

extreme high water spring tide (usually near March and September equinoxes).

extreme low water spring tide (usually near March and September equinoxes).

skeleton supporting body from within.

(adj.) of the epipodium (collar or circlet running round sides of foot of some gastropods)

<p>collar or circlet running round sides of foot of some gastropods, bearing bosses, lobes and / or tentacles</p>

tissue forming outer layer of body surface.

of non-parasitic sedentary animals living attached to other animals.

able to tolerate a wide variation in salinty.

slender, spindle-shaped, tapering almost equally towards both ends.

quill-like pen of chitin serving as muscle attachment and support in squid etc.

specialised arm on male octopus, squid etc adapted for transfer of spermatophores into female’s mantle cavity

1. of gastropod shells: distance from apex of spire to base of aperture. 2. of bivalve shells: distance from hinged dorsal edge to opening ventral edge.

(of chitons) gills in groove along side of foot extend full length of foot.

same as entoprocta, tiny filter feeding goblet shaped animals.

very strong or broad costa along outer edge of aperture.

(of sea slugs) small plates on rhinophores. (of bivalves) folded layers of ctenidium.

(sing. lamina) thin flat plates

<p>low water spring tide, two periods of a few days each month when tide falls lowest.</p>

sheet of tissue that secretes the shell and forms a cavity for the gill in most marine molluscs (but not in adult nudibranchs), part or all of dorsal body surface when shell absent or internal.

(of chitons) gills, in groove along side of foot, only in posterior half of animal.

on or directed towards the midline of the body.

hind part of the foot.

mean high water level.

mean high water spring tide level (level reached by highest tides for a few days every fortnight, Pelvetia zone on rocky coasts).

mid tide level.

(collective noun) animals that swim freely in pelagic zone (main body of water). cf. "plankton".

(adj.) swims freely in pelagic zone (main body of water).

ejectile toxic stings produced by hydroids, sea anemones etc. (Untriggered ones are ingested by predating aeolid sea slugs and stored at the tips of their cerata for defence.)

community of micro-organisms living in the surface film of water

(adj.) of the back.

(of sea slugs) the dorsal surface.

horny plate, sometimes calcareous, used to close shell aperture.

pair of tentacles on or near anterior edge of head near mouth.

flat anterior extension of head.

large exhalent opening on some sponges.

(adj.) embryos develop in egg after laying.

hermaphrodite organ serving as both ovary and testis

(adj.) embryos develop inside egg within mother (but separated from her by persistant egg membrane). Young born from mother after, or as, eggs hatch.

<p>(salinity) parts salt per thousand parts water (brackish &lt;30ppt).</p>

(adj.) of the mantle.

(on bivalves) internal line parallel to ventral margin of valve, marking attachment position of mantle lobe.

(on bivalves with long siphons) indentation in pallial line near posterior of valve where siphons withdraw.

flaps of the parapodium (fleshy structure used in locomotion) which extend up the sides of some opisthobranch molluscs.

(adj.) reproducing without fertilization by male.

quill-shaped chitin serving as muscle attachment and support in squid etc.

sac containing heart, visible behind rhinophores in translucent aeolid sea slugs.

thin horny layer of chitinous material often coating shells.

<p>animals and plants that drift in pelagic zone (main body of water). cf. 'nekton'.</p>

at the front of the foot.

adapical end of growth line or costa tilted forward of the abapical end, so is nearer the aperture.

towards the centre of the body or point of attachment.

chemo-receptor tentacles; nudibranch sea slugs have a pair on top of head.

roughened, corrugated or wrinkled.

ink ejected by cephalopods (octopus, squid, cuttlefish).

1. of immobile animals living attached to substrate, other animals, seaweed etc. 2. lacking a stalk.

extension of mantle to form a channel for respiratory water current.

grooved or tubular extension of outer lip of the shell aperture on some snails, to support the siphon.

unable to tolerate a wide variation in salinity.

just below the apex.

below surface of skin.

below level of low water spring tide

a short distance from the end.

groove or line where whorls adjoin.

(of gill plume) threefold branching; "boughs, branches, twigs" in one plane like a feather.

narrow slit opening of umbilicus on some gastropods

cavity up axis of some gastropods, open as a hole or chink on base of shell, often sealed over.

(of gill plume) branching singly; boughs but no subsequent branches or twigs, in one plane like a feather.

(pl. varices). Very strong or broad costa (rib) along edge of aperture (labial varix), or at previous position of labial varix during growth.

layer of material applied to (usually) inside of conchiolin layer of operculum.

shelled larva of marine gastropod or bivalve mollusc which swims by beating cilia of a velum (bilobed flap).

bilobed flap on veliger larva, with beating cilia for swimming.