GLOSSARY. 399 



Branchiae— The gills. 

 Brittle-Star— One of the Star-fishes. 

 Bryozoa — See Polifzoa. 



Byssus — Silky filaments by which Mussels and other shell-fish attach them- 

 selves firmly to the rocks. 



C^CAL — The ccecum is a bliiul tube ; csecal prolongations of the intestine are 

 therefore ramifications without openings at the farther ends. 



Calamart — One of the Cephalopoda {Loligo), vulgarly called "Squib," and 

 often confounded with the Cuttle-fish. 



Cephalic — Belonging to the head. 



Cephalopoda — Molluscs having long prehensile arms projecting from the 

 head — e. g. the Cuttle-fish. 



CiLLA — Microscopic hairlike bodies which constitute the sole organs of loco- 

 motion in some animals, and which, by their incessant vibration, cause cm-- 

 rents in the water. Ciliary action has nothing voluntary in it, and con- 

 tinues long after the death of the animal. 



CiLlOBRACHlATE — Animals having ciUa on their tentacles. They were for- 

 merly supposed to be Polypes, and distinguished only by the i^resence of 

 cilia on the tentacles. They are now classed as Polyzoa. 



CiRRiPEDS, or CiRRlPEDA — A class of articulated animals having curled and 

 jointed feet. 



Cla YELLING — Compound Ascidians. (Frontispiece, fig. 4.) 



Crassicornis — A species of Sea Anemone, also called the Coriaceous Anemone. 



Crustacea — A class of articulated animals having a crust, or thick skin, 

 which they shed periodically — e. g. Lobsters, Shrimps, Water-fleas. 



Daisy — A species of Sea Anemone : Actima Bellis. 



DiANTHDS — A species of Sea Anemone : the Plumose Anemone. 



Differentiation — When one tissue — e. g. cartilage — is converted into another 

 — e. g. bone — it is said to be differentiated. The process bj- which the fluid 

 mass that constitutes an egg becomes converted into a bird, is a j)rocess of 

 differentiation. Growth is mere increase of bulk ; differentiation is the 

 appearance of new matter or new forms. 



DlCEClOUS — Plants or animals of separate sexes. 



Doris— A Mollusc of the Nudibranch order. (See Plate IL, fig. 2.) 



EcHiNODERiiATA — Animals having spinous coverings, as Star-fishes, Sea-eggs, 

 Sea-urchins, &c. 



Endosmosis — The passage of one fluid, through a membrane, to another fluid. 



Entomostraca — Little Crustaceans, popularly called Water-fleas. 



Entozoa — Parasitic animals which live inside the bodies of other animals. 



Epizoa — Parasitic animals which live outside the bodies of others. 



EOLIS— A Mollusc of the Nudibranch order. (See Plato IL, fig. 1.) 



Epithelium — A delicate membrane covering mucous membranes, as the epi- 

 dermis covers the skin. 



