174 UPPER, OR FLINTY CHALK. 



internally it possessed a surface covered with the apertures of numerous 

 tubuli, in all probability the openings of absorbent vessels, by which its 

 nutrition was effected. 



These inferences naturally present themselves, even upon a shght in- 

 spection of the fossils above described. It has aheady been shewn that 

 the specimens occur in every intermediate form, between that of a simple 

 elongated cone, and a flat circular disk ; hence it is obvious, that the sub- 

 stance of the original must have been soft and elastic, susceptible of 

 spontaneous expansion and contraction, or it could not have accommodated 

 itself to such a variety of shapes, without fracture or laceration. The 

 fibres composing the external integument, are nearly straight in the 

 expanded specimens, but are corrugated and moniliform in those which 

 are contracted ; the thickness of the latter is also much greater than in 

 the former examples ; — circumstances that strongly corroborate the 

 opinion here advanced. 



The expanded state of the animal, might be favourable for the discovery 

 of the substances destined for its nutriment, and which by its subsequent 

 contraction, would been closed in its funnel-Hke cavity. Whatever may 

 have been the nature of its aliment, it seems probable that it underwent 

 a certain degree of digestion and assimilation before it was fitted for its 

 support ; and that the nutritious particles were taken up by the openings 

 so numerously distributed on the inner surface of the ventricular cavity. 



Whether the recent ventriculites were confined to one spot, or pos- 

 sessed a certain degree of locomotion, and by detaching their radical 

 processes, were able to change their situation by floating in the water, 

 cannot with certainty be determined ; but it seems more probable, that, 

 like the alcyonia, and actinicB, they were permanently fixed to the rock 

 upon which they grew. 



The annexed outlines will perhaps serve to render the subject more 

 intelligible than mere description. 



