MEDUSA'S HEAD. 737 



it is difficult to tear it from its hold. When violence is used, it catches hold of its 

 support or any other object within reach with the tips of its arms, which it hooks down 

 for the purpose, and with its pinnae, so that it seems furnished with so many claws, the 

 hard stony nature of which is revealed by the creaking scratching noise they make as 

 they are forced from any hold, as if they were made of glass. 



I was surprised to observe that several of the arms were unsymmetrically short ; and 

 on examining these with a lens, saw distinctly that each had been broken off, and was 

 renewed j the new part agreeing in structure and color with the rest, but the joints 

 were much less in diameter ; and this difference was strongly marked at the point of 

 union, the first of the new joints being not more than one-third as wide as its predecessor. 

 The appearance much reminded me of a lizard renewing its tail. 



In sitting, the Feather-star bends its arms with a sigmoid curve, the tips bending 

 upwards. It waves them now and then, but not much, and remains long without 

 moving from its hold. Though I repeatedly took it out of water, removing it forcibly, 

 it manifested no tendency to voluntary dislocation. 



Perhaps, however, the strangest part of the Comatula's life is its early youth. 



Every one who has the least smattering of geology is familiar with the fossils called 

 Encrinites, and is well acquainted with them under the different popular names that 

 they bear. They are, or rather were, Echinodermata set upon a long flexible stalk, 

 and being constructed, like the Star-fishes, of an enormous number of joints. Popu- 

 larly they are known by the name of Stone-lilies, or Screw-stones, and their disjointed 

 members are very familiar under the title of St. Cuthbert's Beads. The number of 

 joins in an adult Encrinite is almost incredible. 



In the head only of one specimen, no less than one hundred and fifty thousand joints 

 have been calculated to exist, exclusive of the numerous parts of which the stem is com- 

 posed. These joints are frequently found separated from each other ; and as they are 

 perforated by a small hole through which a thread might be run, they were formerly 

 strung together and used as rosaries. Encrinites were found very plentifully in many 

 marbles, which, according to Dr. Buckland's energetic language, are as entirely made up 

 of the petrified remains of Encrinites as a corn-rick is of straws. These wonderful 

 beings could hardly be dissected out of the stone by any exertion of human labor, but it 

 is found that water will achieve a task at once too laborious and too delicate for human 

 hands to undertake. It often happens that the abrupt faces of marble cliffs exposed 

 to the weather, so that the annual rains are driven forcibly upon them, and by their 

 continual action wear away the soft surrounding substance of the stone, leaving the 

 harder forms of the Encrinites as memorials of the time long passed away. 



The Encrinites have long ago perished, but there are still some existing species of 

 stalked Echinodermata, which are closely allied to them, and are still more nearly 

 connected with the history of the Feather-star. These are termed Pentacrinites, because 

 their joints are five-sided. Many fossil species of Pentacrinites are found, and are seen 

 in positions which seem to prove that they must have been adherent by their bases to 

 floating objects, and thus carried about from one place to another, like the barnacles, 

 which have already been described and figured. 



ONE living species of these strange creatures is still in existence, and is shown in the 

 accompanying illustration. This strange being is appropriately called by the name of 

 Medusa's Head, as the many arms that wave about its summit bear some resemblance 

 to the fabled head of Medusa, with its burden of venomous serpents. 



It is not a very large species when compared with some of its fossil relatives, for the 

 largest specimens hitherto discovered are only a few feet in length, and have a stem 

 about as large as a common drawing-pencil. Several fossil species, on the contrary, 

 are at least eleven or twelve feet in length, and measure a full inch across the stem. 

 The MEDUSA'S HEAD is the only species at present known, though it is probable that 

 others may be yet discovered. In the illustration, two specimens of this creature are 

 given, the one to exhibit the head as it appears when expanded, and the other to 

 show its aspect when closed. 

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