268 Dr Hibbert 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. Agassiz'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 demarcation will 

 be sufficiently apparent. For instance, 



The Limestone of Ashford contains The 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. 4. Numerous small fish, as the Palaeonis- 



cus of coal-fields, &c. 



5. Remains of fish referable to the family 5. Remains offish referable to the family 

 of Cestraciontes (Agass.). Genus of Cestraciontes (Agassiz) ; e. g. the 

 not yet ascertained. Gyracanthus formosus. 



6. Other animal remains, which have been 6. Remains of large Sauroid fish; e.g. 



referred to Saurian reptiles. Their the Megalichthys. 



true character is hitherto unknown. 



The foregoing table of comparison, which, for the sole purpose 

 of instituting, I revisited Ashford in Derbyshire, will, I trust, be 

 regarded as important. From a consideration of it, the following 

 inferences may arise : — 



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 



