Dec, 1886.] elliott society. 131 



spection of the same part in a whale 60 feet long, it becomes easy to under" 

 stand tliat that part of the body must have consisted of large bony masses, as 

 it does in the whale ; these were essential to the great muscular power and 

 vigorous movements that doubtless characterized the fossil animal as they do 

 the recent one. Solidity of the vertebral column, the consequence of about 

 the usual proportion of earthy matter m its bones as in the bones of mammalia, 

 must necessarily have been a marked feature of those shark skeletons. 



There are very few of these vertebrae remaining in the phosphate beds, and 

 the presumption is that they have been absorbed in the mass, imparting thus 

 to the lime one of their most important constituents, namely phosphorus. 

 The quantity of teeth however, especially in the river rock, is very great ; but, 

 large as their number is, they do not give an adequate idea of the mass of flesh 

 and bone to which they belonged, until the immense size of the sharks of that 

 period is taken into account. The reason of the teeth not having been absorbed 

 like the bones lies in the enameled surfaces with which they are coated, and 

 which protected them from external influences. To judge of the immense 

 bulk of one of these sharks the outlines of two teeth are here appended. * The 

 large one is of an unusually large specimen of Carcharodon megalodon, and the 

 small one of a recent shark, Gardiarim mdgaris, of the same familj^ 8 ft. in 

 length. If the same relative proportion of tooth to body existed in the fossil 

 sharks as x^revail in the recent, they must have reached a length of from 70 to 

 80 ft. and even more. 



It should be understood that in this opinion as to the source from whence 

 came the phosphorus, the mammalian bones are in no way considered as a 

 source of supply. Their existence in the rivers of the phosphate region is by 

 no means unusual, and it is probable that if the same industry existed elsewhere, 

 of searching the bottoms of rivers for phosphate rock, or other substances of 

 commercial value, the same interesting remains would also be found. As it is, 

 the most perfect bones and teeth of extinct mammalia have be^n found in cer- 

 tain rivers in South Carolina outside of the limits of the most productive beds. 



It becomes necessary, in further explaining the probable cause of this sudden 

 and large extinction of fish life, to allude to a phenomenon which has for some 

 time been a])parent to paleontologists in their investigations into the extinct 

 fauna of Europe and North America. This consists of an evident sudden ex- 

 termination, at a remote period, of a vast amount of animal life in both hemi- 

 spheres. The observations have been made principally as to mammalian life, 

 and the writer is not aware that similar observations have been yet made of the 

 same phenomenon as evidenced in the phosphate beds of South Carolina, 

 There is no reason however for doubting that the sam3 cause, which is believed 

 to have produced this rapid destruction of animals in the Northern parts of both 

 hemispheres, operated with equally fatal results as far South as the 32^ of lat- 

 itude, upon a class of animal life peculiarly susceiDtible to cold. 



There has baen no general agreemant among the scientific as to th3 way in 

 which the glacial jDeriod manifested itself. Of the many opinions advanced, 



* Plate 1. 



