GEOLOGICAL EXPLORATION 
247 
found of soft calcareous sandstones or limestones (Wajhir, 
Eil Wak), the age of which cannot now be definitely fixed. 
Evidences of the desiccation of the country were, it was 
thought, shown (1) by the “ laks ” or water- channels character- 
istic of Jubaland, which contained surface water only during the 
rainy season, and then 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 the lecturer 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 regarded all the ammonites as referable 
to Perisphinctes and its section Virgatosphinctes, and to species 
which had previously been described from the neighbourhood 
of Mombasa. From this assemblage of forms he concluded 
that the shales of Kukatta were of Upper Oxfordian (Sequanian) 
Age. He stated that the belemnite from Serenli indicated 
the presence there of a slender sulcate form, similar to those 
previously recorded from British Somaliland on the north 
and from the neighbourhood of Mombasa on the south ; but, 
although of Jurassic age, it was too imperfectly shown in the 
rock-fragment for accurate determination. 
Mr. R. Bullen Newton said that he had examined a small 
series of non-marine Kainozoic molluscan remains belonging 
