52 JOURNAL OF THE 



roundish cavity, with a smooth inside, or sometimes 

 marked by li^rht ridg-es, which may be accidental; the 

 opposite side is supplied with a rounded knob, from 

 the base of which the radiating groves begin. "^ In the 

 larger, or pala^otrochis major the rounded knob and op- 

 posite cavity are absent. 



''This fossil is a silicious coralline, and not silicious 

 from petrification. It seems never to have had a cal- 

 careous skeleton like most corallines: but, during its. ex- 

 istence, to have been entirely composed of the former 

 substance. The animal was gemmiferous — the germs 

 being sometimes cast off, in which case new and inde- 

 pendent individuals were produced; on others, the 

 germs adhered to the x^a-rent. These start from the 

 circular edge at the base of the cones; their growth 

 produced a change of form which is illusrtated in Figs. 

 2 and 4.2" 



"The palaiotrochis is found at Troy, Montgomery 

 count3% at Zion about twelve miles south-west of Troy, 

 where the fossil occurs in the greatest profusion. It 

 has also been noticed on the road from Troy to Bir- 

 ney's bridge."'^ 



Shortly after the description of the palaiotrochis 

 was published. Professor James Hall, in a letter to 

 Professor Dana,'* suggested that these forms were 

 merely concretions. In 1868, Professor O. C. Marsh 

 in an article on this subject in the American Journal of 

 Science says that he suspected that they were inor- 

 ganic and an examination of the interior clearly indica- 



1. Geolog-ical Report of the Midland Counties of North Carolina 

 E. Emmons, p. 62. 



2. Ibid pag-e 63. 



3. Ibid pa^-e 64. 



4. American Journal of Science Vol. XL<V. p. 218, 



