ELISHA MITCHELIv SCIENTIFIC SOCIETY. 51 



Carolina, on plate 14 opposite pa^^e xx., lie gives a 

 section of the region in which the palasotrochis is 

 found, which is reproduced in Fig-. 1. On page 61 of 

 the same is the following descriptive section, enumer- 

 ated in the ascending order: 



1. Talcose slates, passing into silicious slates, and 

 which are often obscurely brecciated. Thickness un- 

 determined. 



2. Brecciated conglomerates, 300-4-00 feet thick, 

 and sometimes porphyrized. 



3. Slaty Breccia, associated with hornstone. 



4. Granular quartz, sometimes vitreous, and filled 

 with fossils and silicious concretions of the size of al- 

 monds; 200-300 feet thick. 



5. Slaty quartzite, with a very few fossils, about 50 

 feet thick. 



6. Slate without fossils, 40 feet thick. 



7. White quartz, more or less vetrified, filled with l"os- 

 sils and concretions; 700-800 feet thick. 



8. Jointed granular quartz, with only a few fossil;-. 



9. Vitrified quartz, without fossils; 30 feet thick. 



10. Granular quartz, no fossils, and thickness very 

 great, but not determined. 



He says that some of the rock beds in which these 

 forms occur consist almost entirely of them, and are 

 intermixed with almond shaped silicious concretions 

 "v/hich frequentl}^ contain the fossil." He speaks of 

 their occurrence from the size of a small pea to two 

 inches in diameter, but b}' far the greater number be- 

 long to one or the other of two sizes; the smaller size 

 represented by Figs. 2 — 4, and the larger by Figs. 8 

 and 9. The smaller he calls pala^otrochis minor, and 

 in addition to the characters given above, "the apex of 

 the inferior size is exca.vated, or provided with a small 



