ECHINOMYIA. 



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their structure ; they are invested with a well- 

 organised skin, often armed with points, or with 

 spines which are articulated and moveable, and they 

 have an internal cavity which contains distinct 

 viscera. They have also a sort of vascular system, 

 which extends to all parts of the body, and maintains 

 a communication between these and the intestinal 

 canal, and also the organs of respiration, which are 

 often exceedingly distinct. There are also filaments 

 ramified through the system, which appear to answer 

 the purposes of nerves, though these are not always 

 so regular as the corresponding parts of the system 

 in some other divisions of the invertebrated animals. 

 Cuvier divides them into two orders : those which 

 have feet, or at all events organs which answer 

 nearly the same purpose, and those which have no 

 feet. 



The echinodermata with feet are, of course, dis- 

 tinguished from the others by their organs of motion. 

 Their skin or covering is pierced with a great number 

 of small holes arranged in regular series, through 

 which there pass cylindrical tentacula of a membranous 

 substance, terminated by small discs, which are un- 

 derstood to perform the office of aeration. The 

 portions of the tentacula which are in the interior of 

 the body are vesicular, and a liquor which is con- 

 tained in their cavities is sent at the pleasure of the 

 animal to the external cylindrical part, by which 

 means that part is erected, and each of the pro- 

 jections answers the purpose of a little foot, by means 

 of which the animals perform their progressive 

 movements. 



The echinodermata have numerous organs. They 

 have muscles which are very distinct, and serve to 

 execute movements which are often complicated as 

 well as rapid. They are understood to be of two 

 sexes, though these are often united in the same 

 animal, and they are exceedingly prolific. 



The order under consideration consists of a good 

 many genera, of which the principal are asterias, or 

 sea star, which are common on many of the rocks on 

 the British shores ; encrinus ; echinus, sea hedge- 

 hogs, or sea eggs, which are often gathered upon our 

 shores, and are covered with a shell beset with 

 spines ; and holothuria which have an oblong body 

 covered with a leathery crust, and are open at both 

 ends these abound in many seas, are plentiful in the 

 Mediterranean, and the Malays collect vast numbers 

 of them in the eastern seas, the Chinese being very 

 partial to them as an ingredient in soups. The 

 whole of this division or order are inhabitants of the 

 sea ; and though their distribution is pretty general, 

 they are most plentiful in the warm latitudes, and are 

 never found at any great depth. In the tropical 

 seas, where the water is very transparent, where the 

 perpendicular rays of the sun carry their powerful 

 influence to the bottom, and where, in consequence, 

 the production of life is very great, these animals 

 present a very splendid appearance, from the pecu- 

 liarity of their forms, and often from the richness of 

 their colours. They are shown as -sea cucumbers 

 and a variety of other names, according to the fancy 

 of those persons whose notice they attract, and who 

 are not acquainted with the names given to them by 

 naturalists. 



The second order, or the Echinodermata withoul 

 feet, are by no means so numerous as the first ; anc 

 they all bear some resemblance in their general form 

 to *the genus Holothuria. They, however, want the 



small vesicular feet with which the species of that 

 genus are furnished, and are covered with a leathery 

 skin without any appendages. The genus Mol- 

 pudia also, like Holothuria, have a thick cylindrical 

 Dody, open at both ends, and they have the mouth 

 surrounded by osseous pieces ; Minyas, which have 

 the body in form of a spheroid depressed at the poles, 

 which are the two openings, and formed into seg- 

 ments along the sides, something after the manner of 

 a melon ; Pirapulcs, which have a cylindrical body 

 enlarged at the head, and a fasciculus of filaments at 

 the opposite extremity ; Tethodei-mes, which have the 

 body oval, compressed in front, and with a surface 

 incrusted with little grains which are often very hard ; 

 Siphuncuhis have the body cylindrical, and they bury 

 themselves in the sand of the sea in some countries 

 these are much sought after as articles of food ; 

 Bonellia have the body oval, capable of being much 

 elongated and forked at its extremity, they live very 

 deep in the sand ; and Thalassema, which have an 

 oblong oval body but not forked like the former, they 

 also live in the sand. The genera of this last order, 

 which bury themselves in the sand, are generally 

 known by the name of worms. 



The whole of the division are singular animals ; 

 and it is impossible to imagine anything finer than 

 their internal organisation, or more complicated than 

 the number of their parts. They are all without 

 heads, or feet properly so called, or any organs to 

 which we could impute sensation in our ordinary 

 judgment of animals ; but notwithstanding this, they 

 are so numerous that it is impossible not to suppose 

 that the functions which they perform in the grand 

 system of nature's operations, are of no ordinary 

 importance. Those which are not covered with a 

 sort of shell or crust, have very much the appear- 

 ance of living pieces of jelly, or at all events of very 

 soft fleshy matter. Many of these are of a pleasant 

 taste and highly nutritious quality ; but there are 

 others which are not only poisonous when eaten, but 

 which are understood to impart poisonous qualities 

 to those fish which feed upon them. The most inte- 

 resting ones met with upon our shores are the sea 

 hedge-hogs and the star-fish. The former are most 

 frequently found only as empty crusts, with all the 

 projecting tentacula broken off. They are in general 

 shaped something like an apple, with a small aperture 

 on the top which has been the mouth, and its still 

 smaller one at the opposite extremity. The more 

 minute apertures to which the spines have been 

 attached, are arranged in regular rows, reaching nearly 

 from the one opening to the other, something in the 

 same manner as the meridians do on a globe. They 

 are most abundant on the west coasts, and after the 

 Atlantic has been agitated by storms. The sea-stars 

 or star-fish, are found on most parts of the rocky 

 shores at low water, adhering to the rocks by means 

 of filaments ; and they are easily known by their 

 star-like shape. 



ECHINOMYIA (Dumeril). A genus of dipte- 

 rous insects belonging to the great family Muscidce. 

 or true flies, having the nose not prominent, the 

 cheeks not produced into horns, the bristle at the 

 extremity of the antennae simple ; the second joint of 

 these organs is longer than the others, and the third 

 is broader, compressed, and somewhat triangle-shaped. 

 The type of the genus is the Musca grossa, Linnaeus, 

 one of the largest British dipterous insects, being 

 about the size and having much the appearance of 



