268 Dr Hiszert on the Limestone of Burdiehouse 
of new genera, remain to be described. I also obtained Ichthy- 
odorulites, along with palatine and incisive teeth, severally refer- 
able to M. Acassiz’s family of Cestraciontes. At the same time, 
I did not find in the limestone any entomostraca, or any remains 
of smaller fish whatever, as at Burdiehouse. 
In comparing, then, the limestone of Burdiehouse with that 
of Ashford, it will be found that most assuredly these two ap- 
proach the most in character to each other. Yet still, in form- 
ing a table of comparison, such as the following, which I offer 
from my own personal observation, the line of demareation will 
be sufficiently apparent. For instance, 
Tue LIMESTONE OF ASHFORD CONTAINS Tue Limestone OF BuRDIEHOUSE CONTAINS 
1. Encrinites, Corallines, Producti, Or- 1. No marine remains whatever. 
thoceratites, &c. in infinite abundance. 
2, Plants, which are found very sparing- 2. Plants in the greatest possible profu- 
ly, and in a few sites only. sion. 
3. No Entomostraca whatever discovered.. 3. Entomostraca, in such abundance as 
to occasionally impart to the lime- 
stone an oolitic character. 
4. No remains of small fish. . Numerous small fish, as the Palzeonis- 
cus of coal-fields, &c.- ‘ 
5. Remains of fish referable to the family 5. Remains of fish referable to the family 
of Cestraciontes (Acass.). Genus of Cestraciontes (Acassiz) ; ¢. g. the 
not yet ascertained. Gyracanthus formosus. 
6. Other animal remains, which have been 6. Remains of large Sauroid fish; e. g. 
regarded as important. 
Their 
true character is hitherto unknown. 
referred to Saurian reptiles. 
the Megalichthys. 
The foregoing table of comparison, whieh, for the sole purpose 
of instituting, I revisited Ashford in Derbyshire, will, I trust, be 
inferences may arise :— 
From a consideration of it, the following 
1st, While the great abundance in which Corallines, En- 
crinites, Producti, or Orthaceratites, are found in the limestone of 
Ashford, prove that it was unequivocally a marine formation, the 
