133 



work is so much indebted, found on the road, in the neighbourhood 

 of Islington, the flint stone, Plate XIL Fig. 10, which will serve, in 

 some measure, to connect these fossils together. On the side may 

 be seen, a little magnified, the external surface of the organized 

 body, formed of similar inosculating tubes, with those which are seen 

 on the surface of the preceding fossil. In the fore -part is seen a sec- 

 tion of its internal substance, also a little magnified, in which the 

 marks, occasioned by the various convolutions of these tubuli, are 

 beautifully displayed, being of an opaque grey, whils-t the intervening 

 transparent, silicified alcyonic matter is of a strong reddish brown ; 

 shewing that the red colour belonged to more than one species of the 

 antediluvian alcyonic genus. 



The flint fossil, Plate XIL Fig. 7> found in the gravel at Seward- 

 stone, in Essex, is evidently of the same species with the two preced- 

 ing fossils. On its superior part, the convoluted tubuli are seen ; but 

 its inferior part is quite smooth, and appears like the external coat of 

 the alcyonium. This part is extended in such a form as to give rea- 

 son to suppose that the alcyonia of this species, like the preceding, 

 were supported by a peduncle. 



The flint fossil, Plate XII. Fig. 12, is of very doubtful origin. The 

 confused <ind indescribable mass in the centre, now perfectly silicious, 

 I suspect, must have been of an alcyonic nature. Flints, distinguish- 

 able by the circularly disposed traces observable in the lower part of 

 this specimen, are very frequent* 



