The _star-fish_ has five perfectly equal arms. They resemble a cross of honour, which has five branches. The _star of the brave_, the _star of honour_--these somewhat trivial words recall, nevertheless, the resemblance which exists between the two objects; doubtless, man has here taken Nature for his copy. It must, however, be remarked that, though five is the general number of lines in the star-fish, this number is not constant; it varies with different genera, species, and even with individuals. The connection of the arms with the disk presents equally remarkable differences. In the genus _Culcita_, the disk is so much developed that it constitutes, so to speak, the entire animal, whilst the arms form only a slight protuberance upon its circumference. In the genera _Luidia_, on the contrary, the disk is reduced to minimum, whilst the arms are of great length and very slender. [Illustration: Fig. 105. Asterias rubens (Lamarck).] The colours of the _star-fish_ vary greatly; they vary from a yellowish-grey, a yellow-orange, a garnet-red, to a dark violet, as their name indicates. _Star-fishes_ are exclusively and essentially beings of the sea; they are never seen in fresh water; they dwell amongst the submarine herbage, seeking for sandy coasts; they generally are found at moderate depths, but there are some species which are found at the great depth of a hundred and fifty fathoms. Asterias are met with in almost every sea and under all latitudes, but they are most numerous and their forms are more richly varied in the seas of tropical regions. There are about a hundred and forty species described. [Illustration: Fig. 106. Asterias aurantiaca (Lamarck).] The body of the Asteria is supported by a calcareous envelope composed of juxta-posed pieces at once various and numerous. The number of these pieces is estimated at more than eleven thousand in the Red Sea Star-fish (_Asterias rubens_, Fig. 105), a species very common in Europe. The body of the _Asterias rubens_ is likewise furnished with spines, granules, and tubercules, the shape, number, and disposition of which serve to characterise the genera and the species. Another species, _Asterias aurantiaca_, will give an exact idea of the general type of animals of this order. This zoophyte, which is represented in Fig. 106, is common in the northern seas; it has five rather long arms, furnished with spines which are of an orange colour--hence its name. When we see one of these animals stranded upon the shore, it appears to be entirely destitute of all power of progression. But the _star-fish_ is not always immovable; it is provided with an apparatus for locomotion, which appears to serve at the same time the purposes of respiration; for nature is not sparing in her gifts to the least organized beings; she bestows upon them feet, with respiratory organs, or lungs, which have the power of locomotion.