Reports & Proceedings—Geological Society of London. 43 
extremely rarely, if ever, throughout their length; (2) by the 
presence of freshwater molluscs in the scarcely consolidated beds 
of such Laks and at other places where now no surface-water is 
present (Buna and near the Abyssinian frontier); and (3) by the 
presence of wells along fault-lines and in other places where, but for 
the previous presence of springs, it appears improbable that the 
natives would have begun sinking. 
The region between Lake Rudolf and Marsabit was pointed out as 
one of exceptional interest, which the speaker had so far not been 
able to investigate. 
The depression between the Mathews and associated ranges and 
the Abyssinian frontier on which the Marsabit and Hurri volcanoes 
were situated, and the origin of the Kuroli Desert (Elgess), were 
the outstanding features of the district that required further 
elucidation. 
Mr. G. C. Crick stated that the Cephalopoda submitted to him by 
Mr. Parkinson consisted chiefly of crushed ammonites from dark-grey 
shales at Kukatta on the Juba River (lat. 2° 8’ N.), there being also 
a belemnite preserved in a yellowish-brown rock-fragment from 
Serenli on the same river and somewhat north of Kukatta. He 
concluded that the shales at Kukatta were of Upper Oxfordian 
(Sequanian) age. 
Mr. R. Bullen Newton had examined a small series of non-marine 
»Kainozoic molluscan remains belonging to recent species, and 
associated with hard and soft limestones, calcareous sandstones, 
and conglomerates, which had been collected by Mr. Parkinson, and 
had determined about nine genera and twelve species. No vertebrates 
- occurred with these shells, hence their age would probably be younger 
than the Omo-River deposits north of Lake Rudolf, and that yielded 
a somewhat similar molluscan fauna, but with the addition of 
Dinotherium and other vertebrate remains. The presence of that 
genus, as pointed out by Dr. Haug (Zraité de Géologie, 1908-11, 
vol. ii, p. 1727), was indicative of the Pontian or Upper Miocene 
Period. There are, however, some lacustrine beds near Lake Assal, 
in French Somaliland (formerly regarded as Abyssinia), which contain 
shells also bearing a resemblance to those collected by Mr. Parkinson 
in British East Africa, especially MMelania tuberculata, Cleopatra 
bulimoides, Corbicula fluminalis, and C. radiata, which are common 
to both sets of deposits. These Lake Assal beds, which are also 
without vertebrate remains, have been identified by Aubrey (Bull. 
Soc. Géol. France, ser. 11, vol. xiv, pp. 206-9, 1885), and Pantanelli 
(Atti Soc. Toscana Sci. Nat. Proc.-verb., vol. v, pp. 204-6, 1887, 
and ibid. vol. vi, p. 169, 1888) as of Pliocene age. If, from these 
facts, such widely distant beds can be recognized as contemporaneous, 
then the suggestion may be made that the northern half of British 
East Africa was probably an extensive freshwater region during 
Pliocene times, limited on the north by Lake Assal, on the east by 
Suddidima, on the south by Archer’s Post and the Mount Kenya 
plateau, and on the west by Lakes Rudolf, Stefanie, and Marguerite. 
Assistance in the determination of these shells had been kindly 
rendered by Mr. E. A. Smith, 1.8.0. 
