8 



Bradford Clay and its Fossils. 



subjected to the action of the waves after they had fallen down upon 

 the bottom of the sea, which could not have been the case had they 

 been suddenly covered up with a considerable bed of clay. Instead 

 of the catastrophe of mud, it is I think more probable that the clay 

 was very gradually deposited; and as it accumulated, it would in 

 process of time, form a sea bottom totally unfit for the attachment 

 of the roots of these animals. They could not fix themselves upon 

 a bed of soft clay, and consequently, although their remains are 

 found thinly scattered through some of the upper rocks, they 

 ceased to exist in this particular neighbourhood, as soon as the 

 change in the sea bottom rendered it unsuitable to their habits. 

 It is most probable, that like the fry of many other animals (the 

 oyster, &c.,) which are fixed to the rocks in the adult stage of 

 their existence, the young Apiocrinites were furnished with organs 

 of locomotion, so that they could rove about and suit themselves as 

 to the place of their permanent habitation. 



D'Orbigny the French naturalist, speaking of the habitation of 

 the Apiocrinidce says, "All the species being fossil, it would seem 

 difficult to define their mode of existence. If, however, I may 

 judge from the places where they lived, and where I have found 

 them in abundance, still in situ, I should say that in the lower 

 coral banks of the different geological epochs, they lived in the 

 great cavities of the coral rocks. Here at least, near Eochelle, my 

 father and I have always found them with their roots, the stem 

 and top being still either in a vertical position, or lying by the 

 side. There is reason to think that they sometimes lived at great 

 depths in the bosom of the ocean, either in places where the cur- 

 rents were but little felt, or in the cavities of the corals, where the 

 waves and currents could not disturb them. There fixed by their 

 roots, their stems erect, their graceful heads crowned with their 

 many flexible arms, they could spread themselves out, and wait for 

 their prey, in a position exactly the reverse of that of the Asteria, 

 and other Echinoderms, which always have the mouth beneath, 

 instead of above them, like the Crinoides." 



The first recognisable figures of Apiocrinites published, were by 

 Luid a Welshman, in 1699 ; but the French naturalists, Bourguet 



