34 
making this statement had it depended on my own limited 
experience, hut I do so with more confidence, as the fact is 
substantiated by the microscopic examination of Professor 
Williamson. He says, what I believe to be the same species 
(of Textularia) occur abundantly amongst other types of 
Foraminifera in the sandy deposits underlying Boston in 
Lincolnshire, but I never discovered it living in the sea. 
From unknown causes it has disappeared. On the other hand 
our modern deposits abound in Diatoms and Radiolaria of which 
no trace appears in the true cretaceous beds. That in the 
depths of the Atlantic, cretaceous and modern deposits may be 
conformably and continuously supposed is not impossible, but 
conformable continuity of series does not constitute identity of 
age or formation. In the Speeton clay of the Yorkshire coast, 
we have in the same blue deposit a transition from the oolite to 
the Cretaceous beds. The deposits have continued to ac¬ 
cumulate without physical change from one age to the other, 
but the formations to which the lower and upper portions of 
this clay belong are distinct and represent distinct epochs.” 
Dr. Carpenter is disposed to consider that the higher forms of 
the Atlantic and Cretaceous fauna will prove to be nearly 
identical—but even from an authority so eminent as Dr. 
Carpenter this opinion must be received with caution, for 
Ehrenberg expressed a like opinion on a similar matter, which 
proved an error, respecting the tertiary beds of the Mediter¬ 
ranean coast. These he regarded as Cretaceous because he found 
that they abounded in Cretaceous types of Foraminifera, over¬ 
looking the wide differences presented by the higher organiza¬ 
tions of the two formations. 
Again in the white chalk of England there is an exceedingly 
beautiful group of fossils called Ventriculites, which have 
greatly puzzled Palaeontologists. They have the form of vases, 
tubes or funnels, ridged, grooved, or otherwise ornamented on 
the surface, frequently expanded into a cup-like lip, and con¬ 
tinued below into a bundle of fibrous roots. Many opinions 
have been held respecting their place in the organic kingdom, 
but it is most probable that they belong to the Porifera 
(sponges), and that the silex of their spicules was removed and 
