Three Skulls of Naloo Africans. 391 



mature character is more frequently retained than in the 

 males. As individual peculiarities there may be noticed the 

 deep and almost symmetrical grooving of the frontal bone by 

 the supra-orbital nerves and vessels in A. The same cha- 

 racter is more feebly repeated in C. 



The general cranial characters of the Ethiopian race are 

 manifested in all, by the narrow anteriorly contracted oval 

 cranium, by the prognothic jaw, and by the protuberant 

 cheek-bones ; but they are most strongly marked in A and 

 C, except that the cheek-bones shew the sexual inferiority 

 of development, together with the weaker zygomata in the 

 female skull C* 



On the Succession of Strata and Distribution of Organic Re- 

 mains in the Dorsetshire Purbecks. By Professor EDWARD 

 Forbes, F.R.S.t Communicated by the Author. 



During the autumn of 1849, Professor E. Forbes was deputed 

 by the Director- General of the Geological Survey, Sir Henry De la 

 Beclie, to examine the organic remains of the Purbeck strata in 

 Dorsetshire, and to investigate their distribution in situ, acting in 

 co-operation with Mr Bristow, the officer engaged in constructing 

 the geological map of the district. The results of this enquiry were 

 so novel and curious, that it was thought by the Director-General 

 desirable, before publication in an extended form, to lay them be- 

 fore the British Association, in the hope that, by such a course, 

 attention may be directed to similar phenomena in freshwater for- 

 mations in other districts. 



Our knowledge of the Dorsetshire Purbecks has been derived 

 chiefly from the memoirs by Professor Webster, Dr Fitton, Sir H. 

 De la Beche, Dr Buckland, and Dr Mantell. With the exception 

 of certain Vertebrata (reptiles and fishes) we owe to Dr Fitton our 

 information respecting their fauna. No minute investigation of the 

 strata in connection with their organic contents had, however, been 

 undertaken, nor had the latter been collected to any extent, as may 

 be seen when the published lists, including about 12 species of Mol- 

 lusca and Crustacea from these beds, are compared with those now 

 submitted to the section, in which more than 70 members of those 

 classes are enumerated. This increased catalogue is not merely of 



* Dr Cull's Observations on the Naloo Skulls will appear in our next Number. 



t The above is a more particular account of the Dorsetahire Purbecks deli- 

 vered at the late meeting of the Uritish Association, and already noticed in a 

 very general way at page 31 1. 



