OCR Text |
Show 34 PROF. W. II. FLOWER ON THE AUSTRALIAN CASSOWARY. [Jail. 3, the frontals, the lachrymals, and perhaps the parietals ; but as all the cranial sutures are obliterated, the limits of the different bones cannot be exactly defined. In the specimen of C. australis, the base of the crest is produced backwards from its point of origin, so as to overlap part of the cranium, leaving a narrow fissure between (see fig., p. 33), whereas in one of the specimens of C. galeatus in the College Museum * the crest at the same spot rises vertically from the cranium. This appeared to be a good diagnostic character, until Mr. Gerrard's specimen was examined and found to agree with C. australis in the mode of origin of the hinder part of the crest, although in other respects it resembled the two College specimens of the species to which it was referred. The anterior portion of the upper jaw, formed by the praemaxilla, is relatively longer, more curved, and more pointed in G. australis than in any of the specimens of G. galeatus; but some allowance must be made for the fact that the former was a wild bird, while the latter had all lived some time in captivity, and may not improbably have blunted or slightly malformed the extremity of the beak by repeatedly pecking the sides of the cages in which they were confined. No important distinction can be traced in the form or arrangement of the bones at the base of the cranium, except that the united palatine and pterygoid is somewhat broader in proportion to its length in the specimen of C. australis than in those of C. galeatus, though it is doubtful whether this is more than an individual peculiarity. In the principal characters of the vertebral column and ribs all three skeletons of C. galeatus agree. They all have 25 free vertebra, in front of the sacrum. Of these, 15 are without moveable ribs, 4 have moveable ribs not connected with the sternum, 5 have moveable ribs connected below with sternal ribs, of which the first four are articulated directly to the sternum, while the fifth does not quite reach that bone, and one is a floating rib. A rib-bearing vertebra (the twenty-sixth from the skull) is ankylosed with the sacrum ; but the rib it carries varies much in size and in characters, being nearly as long as the one in front of it, and quite free, in one specimen, and quite rudimentary and ankylosed to the vertebra in another. The sacrum is composed of about 20 ankylosed vertebrae (not counting the one which bears a true rib) ; and in the two specimens in which the tail is perfect there are nine caudal vertebrae, of which the last three are united together. The skeleton of C. australis differs from these in several particulars. It has 26 free presacral vertebrae. Of these, 19 are anterior to the first one which is connected to the sternum, and hence may be called cervical, the same number as in C. galeatus; but the rib is ankylosed in the sixteenth instead of being free. There are five vertebra} bearing ribs with sternal ribs attached, all of which articulate directly with the sternum, instead of only the first four. Then there are two vertebrae bearing floating ribs anterior to the * In the other this part of the skull had been destroyed in taking out the brain. |