. Cassell's natural history. Animals; Animal behavior. TUB \OJD FJS}r£S. 2i cutting and crushing. Tliere is one jiair of snmll teeth in the fore-part of the jaw wliicli, from thcii- positiou upon a bone called the vomer, are termed vomerine teeth ; they meet each other at a right angle, which is directed forward. The'other teeth are much larger, and are crossed by six strong ridges, which extend inward from the outer margin. Between these ridges are five notches. In a specimen three feet long this tooth is an inch and a quarter long and half an inch wide. The coi-- responding teeth in the l
. Cassell's natural history. Animals; Animal behavior. TUB \OJD FJS}r£S. 2i cutting and crushing. Tliere is one jiair of snmll teeth in the fore-part of the jaw wliicli, from thcii- positiou upon a bone called the vomer, are termed vomerine teeth ; they meet each other at a right angle, which is directed forward. The'other teeth are much larger, and are crossed by six strong ridges, which extend inward from the outer margin. Between these ridges are five notches. In a specimen three feet long this tooth is an inch and a quarter long and half an inch wide. The coi-- responding teeth in the lower jaw have a similar shape, and are so placed as to fit against the- others and form an apparatus for grinding food. The hard parts of the fore-limb are entirely car- tilaginous ; the paddle is joined to the scapular arch by a cartilage which represents the humerus. A median row of cartilages of a quadrate form, twenty-six in mnnber, extends the length of the- limb, and on both sides of it rays are given ofi" which diverge downward and outward. This type of fin is quite unpai-alleled, although the central series of cartilages may be compared to that-of the Lepi- dosiren. Dr. Giinther compared the fin to the tail of an ordinary fish; nor is the plan of structiu-e very dissimilar to the tail of Ceratodus itself. The structure of the hind-limb is quite like that of the fore-limb, except that it is rather more symmetrical and is shorter. The intestine- is nearly straight, and below the stomach is traversed throughout by a spiral valve, which may be compared to that of Sharks and Rays, and winds around nine times. But the most remarkable circumstance about this fish is the fact that it can breathe either by gills or by lungs, or simul- taneovisly by both. The gills are not connected with spiracles, nor is there any true operculum. The- lung is single, and is a wide sac which extends down the middle of the dorsal region, from one end of the abdominal cavity to
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Keywords: ., bookcentury1800, bookdecade1890, booksubjecta, booksubjectanimals
