ZOOLOGY. 19 



Ordor GORGONIACE^E. 



To tliis order belongs the ' red coral ' of commerce, a speeios found in the 

 Mediterranean Sea only, and which has no relation to those lumps of red coral in 

 the form of aggregated pipes {tuhipora musica), which one sees in all coUectious of 

 shells and miscellaneous curiosities from trojjical ports. 



Order TUBIPOllACEiE. 



Coral in the form of tuhes, bound together by horizontal plates. No septa. 

 Polypes completely retractile, those of the common red organ-pipe coral [tahiiiura 

 musica) being of a violet or gTass-grceu colour during life. 



Sub-Kingdom III. ECHINODERMATA. 



"All cchinodenns have a calcareous skeleton, and many are provided with move- 

 able spines. A characteristic apparatus of vessels termed the ambulacral or water- 

 vascular system is pi'csent. It is composed of a ring round the phai-ynx, from which 

 proceed a number of radiating canals commonly giving off cEEcal appendages, as well 

 as branches, which enter the retractile tube-i'eet, often furnished with a terminal 

 disk or sucker, which with the sjiines are the organs of locomotion." (Pasooe.) 



Class CRINOIDEA. 



To this class belong the ' sea lilies,' so numerous in PaJitozoic and Mesozoic seas, 

 and whose joints form no inconsiderable portion of some ornamental marbles. The 

 C'omaluUda of the present seas belong to the same class, the immature Comatida 

 being fixed on a stalk like the old ' sea-lilies,' but the adult animal becoming free 

 and capable of locomotion. 



Class STELLARID.5E. 



Order OPHIUROIDEA. 



The disk is entire and contains the viscera. The arms are attached to, but are 

 not prolongations of the disk, and are formed of four rows of calcareous plates. The 

 arms are devoid of suckers, and are themselves the organs of locomotion. The arms 

 are extremely brittle and are spontaneously detaclu-d, if the animal is molested, 

 whence the popular name of ' Brittle stars ' which they have received. Some species 

 of these ' Brittle stars ' abound under stones at low water on the coast of Burma, but 

 have not been speciflcally identified. 



Order ASTEROIDEA; 



The disk is more or less lobcd, the lobes being prolonged into arms which are 

 channelled below, and contain prolongations of the viscera. The arms are freely 

 provided below with suckers, which constitute organs of locomotion. I'his order 

 embraces the common star-fish of the British coast, which is such a pest to the 

 oyster-banks, that mollusk forming its favourite food, and no doubt the pearl-oyster 

 suffers in a similar manner. Imaginative people have supposed tliat the ' star-fish ' 

 watches its opportunity and adi-oitly inserts a stone between the valves of the 

 oyster to prevent it closing its shell, but this is not credible — the particular induce- 

 ment, however, which the star-fish employs, when desirous of putting himself in 

 communication with the oyster, is not very evident. 



Class ECHINOIDEA. 



This class embraces the multitudinous forms of ordinaiy echinoderms, sea-urchins, 

 sea-eggs, sea-pancakes, etc., numbers of which occur on the coast, but none of which 

 have been speciflcally identified. The flesh of the larger species is esteemed for 

 food. Many species secrete themselves in holes in rocks, and once fairly in its 

 hole, it is a matter of the extremest difficulty to extract the recalcitrant animal 

 ■without damage, so tightly does it grip the sides of the cavity with its spines. 



