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structure of the upper jaw is different from that of the Rhipidistia and 

 of modem bony fishes. The maxillary bones at the side of the upper 

 jaw are missing, there is only a thick fold of skin. The teeth in the 

 upper jaw are set differently from those of modern bony fishes. They 

 are in clusters in separate but adjacent plates. 



The scales bear tubercles, each of which is a strong, separate, 

 enamelled structure stuck on the main base of the scale. Some of 

 these tubercles are smooth all round, but some have a sharp point 

 behind. These tubercles are hollow inside. It has long been held that 

 teeth in jaws are developed from scales that 'migrated' inwards. In 

 the development of a shark it is possible to see something of this, and 

 in the Coelacanth this shows very clearly, for the teeth are in groups on 

 adjacent but separate bases, and examination soon reveals that each of 

 these is merely a modified scale, in which the base has become thicker 

 and stronger, and the hind pointed part of the tubercles has become 

 longer, more bony and strong, sharply pointed, and, in fact, a hollow 

 canine tooth. Even the teeth on the gills are of this form. In addition, 

 some of the surface bones of the head show themselves as no more than 

 modified scales. 



On the floor of the mouth of the Coelacanth there is a hard, bony, 

 toothed structure different from an5^hing in any modern fish. Below 

 the lower jaw are two bony, reptile-like plates, 'Gular Plates', that are 

 found in a few only of the more primitive types of living fishes. 



The fins are certainly curious. The pelvics and pectorals give clear 

 indication of being used as limbs, and it is plain that the fish can crawl 

 about, in the water at least. Ancestral Coelacanths probably crawled out 

 on land. (Old Fourlegs!) 



The tail is characteristic. That small extra tail is not found in modern 

 fishes. It is indeed a remnant of the true tail that is supposed to have 

 been present in ancestral forms. (See also the figure of a Rhipidistian 

 fish, p. 17.) The 'tail' of modern fishes is really evolved from two fins, 

 one above and one below, into which the hinder true 'tail' eventually 

 shrank away. 



The 'skeleton' is remarkable. The 'backbone' or 'axial* column is 

 not of bone, but a hollow tube of cartilage, that fits in front into a 

 hollow in the skull, and behind tapers to a thin rod in the tail. On the 

 backbone of an ordinary fish you see hard, bony spines above and below. 

 The Coelacanth has something like these, but they are hollow tubes and 

 not very hard. (This is how the Coelacanth got its name. 'Coelacanth' 

 means 'Hollow spine'.) At the base of each fin, however, there is a 

 rather large and heavy bony plate, the 'basal' plate, well known from 

 fossils. 



The intestines of a Coelacanth are short and have in them a 'spiral 



