Sclerodermic

(Gr. skleros; and derma, skin). Applied to the corallum which is deposited between the tissues of certain Actinozoa, and is called " tissue-secretion " by Mr Dana.

Sclerotic

(Gr. skleros, hard). The outer dense fibrous coat of the eye.

Scolecida

(Gr. skolex, worm). A division of the Annuloida.

Scolex

(Gr. skolex). The embryonic stage of a Tape-worm, formerly known as a " Cystic worm."

Scuta

(Lat. scutum, a shield). Applied to any shield-like plates; especially to those which are developed in the integument of many Reptiles.

Selachia or Selachii

(Gr. selachos, a cartilaginous fish, probably a shark).

The sub-order of Elasmobranchii, comprising the Sharks and Dog-fishes.

Sepiostaire

The internal shell of the Sepia, commonly known as the "cuttle-bone."

Septa

Partitions.

Serpentiform

Resembling a serpent in shape.

Sertularida

(Lat. sertum, a wreath). An order of Hydrozoa.

Sessile

(Lat. sedo, I sit). Not supported upon a stalk or peduncle; attached by a base.

Setae

(Lat. bristles). Bristles, or long stiff hairs.

Setiferous

Supporting bristles.

Setigerous

(=Setiferous).

Setose

Bristly.

Siliceous

(Lat. silex, flint). Composed of flint.

Sinistral

(Lat. sinistra, the left hand). Left-handed ; applied to the direction of the spiral in certain shells, which are said to be "reversed."

Sinus

(Lat. sinus, a bay). A dilated vein or blood-receptacle.

Siphon

(Gr. siphon, a tube). Applied to the respiratory tubes in the Mollusca; also to other tubes of different functions.

Siphonophora

(Gr. siphon,; and phero, I carry). A division of the Hydrozoa, comprising the Oceanic forms (Calycophoridae and Physophoridae).

Siphonostomata

(Gr. siphon ; and stoma, mouth). The division of Gasteropodous Molluscs, in which the aperture of the shell is not "entire," but possesses a notch or tube for the emission of the respiratory siphon.

Siphuncle

(Lat. siphunculus, a little tube). The tube which connects together the various chambers of the shell of certain Cephalopoda (e.g., the Pearly Nautilus).

Sipunculoidea

( Lat. siphunculus, a little siphon). A class of Anarthropoda (Annulosa), Sirenia (Gr. seiren, a mermaid). The order of Mammalia comprising the Dugongs and Manatees.

Solidungula

(Lat. solidus, solid ; ungula, a hoof). The group of Hoofed Quadrupeds comprising the Horse, Ass, and Zebra, in which each foot, in the living forms, has only a single solid hoof. Often called Solipedia.

Somatic

(Gr. soma, body). Connected with the body.

Somatocyst

(Gr. soma ; and kustis, a cyst). A peculiar cavity in the coenosarc of the Calycophoridoe (Hydrozoa).