132 TWO-LAYERED ANIMALS— PHYLUM COELENTERATA 



uncharted areas in this region. The Florida keys are examples of such 

 islands in our own country. These are surrounded by coral reefs upon 

 which many ships have been wrecked, especially during our early history 

 when small vessels had to go around the southern tip of Florida to reach 

 the cities on the Gulf of Mexico. 



In spite of the great abundance of coral of many varieties, there is 

 one that is referred to as precious coral which may be valued as high as 

 $600 an ounce. This is found primarily in the southern Mediterranean 

 waters and off the coast of Japan. It is usually a pink or red color and 

 makes beautiful bracelets, necklaces, and similar ornaments. It usually 

 grows in water from 90 to 900 feet deep and is a more beautiful sight 

 in its living condition, with the delicate tentacles waving forth from the 

 brilliant skeleton, than it is when it has been made into a necklace. 



Classification and Derivation of Scientific Words 



Phylum. Coelenterata (Gr. koilos, hollow; enteron, intestine; refers to 

 the fact that the body of these animals is somewhat like a hollow 

 intestine). 

 Class A. Hydrozoa (Gr. hydra, water serpent described below; soon, 



animal; these are hydra-like animals). 

 Genus 1. Hydra (Greek myth, Hercules slew a water serpent called 



Hydra which had nine heads and if one were cut off two would 



grow back in its place ; refers to the regeneration of tentacles in 



this genus). 

 Genus 2. Physalia, Portuguese man-o-war (Gr. physallis, a blad- 

 der; referring to the bladder-like nature of the float). 

 Genus 3. Gonionemus (Gr. gonia, angle; ncma, thread; possibly 



refers to the thread-like tentacles hanging down at an angle from 



the edge of the umbrella). 

 Class B. Scyphozoa (Gr. skyplios, cup; soon, animal; refers to shape). 



The large jellyfish. 

 Class C. Anthozoa (Gr. anthos, flower; soon, animal; refers to the 



flower-like appearance of these animals). 

 Genus 1. Metridium, a sea anemone (L. metricas, rhythm; refers 



to the symmetrical arrangement of tentacles and other body 



parts). (Common name from the flower anemone which these 



resemble ) . 

 Genus 2. Astrangia, a coral (Gr. aster, star; angeion, a little vessel 



or receptacle ; refers to the star-shaped little receptacles which 



coral polyps secrete and in which they live). 



