160 Dr. J. 8S. Hyland—Soda-Microcline, Kilimandscharo. 
In north-eastern England it seems worthy of inquiry whether the 
Purple and Hessle boulder-clays may not be in like manner the sub- 
glacial and englacial till of a single ice-sheet, its modified drift being 
the Hessle gravel and sand. If this view be admissible, the Hessle 
beds containing Cyrena fluminalis and mammalian remains, where 
they are overlain by the Hessle boulder-clay, mark an extensive re- 
cession and subsequent advance of the ice.! Again, in north-western 
England the Lower and Upper boulder-clays and Middle beds of 
gravel and sand have the same relationship. These groups of drift 
deposits, bounded wholly or in part by the terminal moraines traced 
by Lewis, probably belong, like the conspicuous terminal moraines 
ot the United States, to the second or last glacial epoch; while the 
Chalky boulder-clay, like the southern portion of the glacial drift in 
the Mississippi basin, extends beyond these to the limits of an earlier 
glaciation. 
1V.—On Sopa-Microciine From KILIMANDSCHARO.2 
By J. 8S. Hytanp, Ph.D., M.A., 
Of the Geological Survey of Ireland. 
HE material, in which this felspar occurs, was collected by Dr. 
Hans Meyer during his visit in 1887 to the East-African “ snow- 
mountain,” the Kilimandscharo, and kindly entrusted to me for 
description by Prof. F. Zirkel of Leipzig, to whom I desire to 
express my indebtedness for assistance and advice supplied me 
whilst working in his laboratory. 
The rocks which possess this mineral as felspathic constituent 
are Nepheline- and Leucite-basanites,* and were found in siti on the 
south and south-east flanks of the Kibo peak. As rock-constituent 
this felspar is presumably confined to the outflows from the higher 
peak—the Kibo *—as no trace of it is to be found in the large series 
of rock-specimens, which represent the materials of which the other 
and lower peak—the Kimawenzi—is formed. 
It is remarkable that Gustav Rose,® who described the collection 
of specimens brought back from the same locality by Baron von der 
Decken in 1861 and 1862, mentions the occurrence in a rock he 
terms “trachyte” of a curious porphyritic felspar “‘ whose crystals 
are rhombic prisms, so that a transverse section parailel to the best 
cleavage face appears as a rhomb.” From his description I hold 
this felspar to be identical with that which Dr. Meyer collected. 
1 Quart. Journ. Geol. Soc. vol. xvii. 1861, pp. 446-456, and 473-5; Great Ice 
Age, second ed. pp. 372-380. 
2 The orthography used by R. Andree and A. Scobel in their Map of Africa 
(Leipzig, 1884) is here employed. 
8 Under ‘: Basanite”” Rosenbusch (Mikrosk. Phys ii. p. 753) includes all Tertiary 
massive rocks, which possess as essential constituents plagioclase (usually a basic 
lime-soda-felspar), nepheline or leucite, augite, olivine and magnetite. ‘The name 
was first employed by Alex. Brongniart (Classification et caractéres minéralogiques 
des roches homogénes et hétérogénes, Paris et Strasbourg, 1827, pp. 102-105). 
This is the first occurrence of Leucite in Africa. For further particulars, see Hyland, 
“* Ueber die Gesteine des Kilimandscharo und dessen Umgebung,”’ Tschermak’s Mitt. 
1888, X. 203-267. 
4 6090 metres high. 
5 Zeitschrift fiir allgemeine Erdkunde, Berlin, 1863, vol. xiv. p. 246. 
