62 Mr Tawney and Mr Keeping, On the beds of [Dec. 6, 



To complete the section, the details of the Upper Headon at 

 Cliff End are described for comparison with this series in Headon 

 Hill ; the thick limestone has thinned from 27 feet to about 2 feet, 

 which is counterbalanced by an increased thickness in the sands. 

 The Osborne Marls succeed having the same characters as at 

 Headon Hill. 



Palceontological evidence. Exception is taken to Prof. Judd's 

 method of mixing fossils from various localities in the same list ; 

 thus he places the fossils from the Colwell Bay, Brockenhurst, and 

 White Cliff Bay marine series in one list, as if these were all 

 from the same horizon, or of the same age, and compares them 

 with another list, containing the fauna of Headon Hill and Hord- 

 well marine — also mingled together, — and from this comparison 

 he finds that less than one half of the fossils in the latter two 

 occur in the former three places, from which it is assumed that the 

 Colwell Bay and Brockenhurst beds are of not the same age as 

 those of Headon Hill — they are conceived to be newer. 



The authors point out that it amounts to begging the question 

 to assume the equivalence of the Colwell Bay and Brockenhurst 

 beds — that is one of the points to be settled — and that nothing 

 can be proved from a list in which fossils from the various locali- 

 ties are commingled. 



Accordingly in the Tables prepared by the authors, the fossils 

 from each locality are given in a separate column, so as to be 

 easily comparable. 



A separate list is however given of forms, which they have 

 collected this year from the Middle Headon of Colwell Bay and 

 Headon Hill, everything in the latter list having been found by 

 their own hands ; out of 57 species at Colwell Bay, they found 53 

 in the middle marine of Headon Hill, a proportion of about 93 per 

 cent.; even of the 4 which are missing most have been found 

 previously. These figures are held to prove the identity of the 

 horizon in the two localities. 



The distribution of one or two leading fossils is then discussed. 

 Prof. Judd has argued that the Headon Hill marine bed is not 

 equivalent to that of Colwell Bay, because it contains Gerithiv/m 

 ventricosum and C. concavum, which, he says, do not occur at Col- 

 well Bay. The authors show that is an error. They point out 

 the position of the one bed at Headon Hill, in which G. ventricosum 

 abounds, and find it o:cupying precisely an analogous position at 

 Colwell Bay. G. concavum has a wider range at Headon Hill, 

 where it is very abundant, since it occurs through the greater part 

 of the Middle Headon there ; the authors have found it however 

 in the " Venus-bed " of Colwell Bay. The distribution of these 

 and other fossils show that the palaeontological evidence is in 



