THE 



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The beautiful Red Coral,* which is used so much as an ornament, is the cleaned hard stem of an 

 Alcyonarian, which lives fixed to substances at considerable depths in the Mediterranean and some 

 parts of the Atlantic and Pacific. The red stem has delicate striations on it, and a section shows a con- 

 centric arrangement of calcareous matter, tinted various shades of red. The animal forms this by deposi- 

 tion of the calcareous grains in a connective tissue, and covers the whole with a somewhat dense soft 

 part. In this there are canals, or water-systems, running over the hard stem, conforming to its mark- 

 ings, and communicating with smaller canals. The soft parts, moreover, above the canals are formed 

 into polypes, or zooids, which are contractile and very extensible. They have a thick base, which 

 narrows upwards to a point, whence a swelling extends, capped by eight feathery tentacles. Muscles 

 exist to retract the zooids, but nerves have not yet been dis- 

 tinguished. A mass of spicules environs the hard stem, and is 

 gradually connected to form the outer layer. The zooids are 

 unisexual or bisexual on the same stem, and the ova form a planula 

 covered with cilia, like a little white worm. It swims freely, 

 and settles down after escaping from the mouth of the parent, 

 remaining permanently adherent to some substance on the floor 

 of the sea. The changes then proceed which lead to the formation 

 of a mouth, stomach, and perigastric cavity ; and the calcareous 

 matter gradually deposited by connective tissue, and forming the 

 stem and the spicules, is derived from the products of digestion. 

 As in the case of the Stony Madreporaria, the carbonate of lime 

 of the skeleton is not got from sea-water, but from the shells of 

 the minute animals which constitute the food. The deposition 

 of the carbonate of lime thus obtained in certain tissues is 

 analogous to the formation of bones in the Vertebrata and shells 

 in the Mollusca. There is a very important coral fishery off the 

 coast of Algeria, near Calle, and also off the east coast of Spain, 

 and the article is systematically obtained by a rude dredging 

 or breaking-off and bringing-up apparatus. The coral fisheries of the coasts of Italy and Sicily 

 begin about the middle of February and continue into October. Pale coral is the most prized 

 now. Off Torre del Greco a large quantity of coral is found every year, and from 400 to 600 

 boats of from six to ten tons are employed. The cost per boat is from 500 to ,600, and the Coral, 

 when good, is worth from 80 to 200 an ounce. Dana describes a branching, more or less fan- 

 shaped Coral, of a pale colour within and brilliantly red outside. It is also found off the Sandwich 



Islands. These species belong to a sub-family the Corallinse and it was 



represented in the age of the Chalk at Faxoe, and in the Miocene of Turin and 



Sindh. 



Other dwellers on the floor of the sea, possessing branched stems, have the 



calcareous part of it not continuous, but in more or less cylindrical or flat pieces, 

 COHALLIUM SPICULE. separated by horny tissue. They are the sub-family Isidinse; and the genus Isis 



has the polypes on the calcareous pieces which are striated. The branches arise 

 from the calcareous parts, his hippuns is from Amboyna, and Isis polyantha from the American 

 seas, whilst Isis coralloides is from the seas of India, This widely-distributed genus has naturally 

 fossil forms, and they have been found in the Cretaceous and Miocene strata of Europe, and in the 

 Miocene of Sindh and Australia. 



In the genus Mopsea, a dweller on the deep-sea floor, the branching takes place from the inter- 

 calcareous or homy part, and there is a fossil Eocene form of it. 



In the genus Melithaea the outer calcareous parts are porous and corky in appearance. 



The sub-family Gorgoninse has a flexible continuous stem which resembles horn more than 



chitine. The environing soft parts are well developed, and the polypes may be sunken in it or 



may project as little warts. There are spicules of carbonate of lime in the soft parts, and sometimes 



there is some of that mineral in the stem. The stem, marked with grooves on the outside, is formed 



* Corallium rubrum. 



COKALLIUM KUBKUM. 



