[68]. Referred to genus 37 of the olivine-basalts.
[69]. On the right side of the river close to Vatu-kawa there are some cliffs displaying a section of the mountainous spur, referred to on p. [151], that separates the valleys of the Mbale-mbale and Vatu-kawa rivers, an exposure quite apart from the rocks exhibited on the adjacent southern slopes of the main range. These cliffs are formed of bedded grey tuffs marked by single layers of blocks 6 to 8 inches across and dipping about 30° S.S.W. The tuffs in their texture are not unlike sub-aerial tuff-deposits. They contain no lime and are composed of basic materials with a little palagonite. They seem to indicate some subsidiary vent, close to the present village of Vatu-kawa, which may have been active shortly before or during the emergence of this district.
[70]. These altered tuffs on the southern slope of this range are described on p. [332].
[71]. Referred to genus 16, species A, sub-species 1, of the augite-andesites.
[72]. Referred to genus 9, sub-genus A, of the augite-andesites.
[73]. Referred to genus 9, sub-genus B, of the augite-andesites.
[74]. Both these rocks belong to the hypersthene-augite andesites, showing phenocrysts of both monoclinic and rhombic pyroxene. The first belongs to the orthophyric order described on p. [290]; whilst the second belongs to the second order (genus 13, p. [287]) where the felspars of the groundmass are lathe-like and in flow arrangement.
[75]. The highest dyke trends N. 48° E. and is inclined from the vertical about 15° N.W. The dyke, 5 or 6 yards below it, trends N. 30°E. and is vertical. The dyke, 50 yards farther down, trends N. 35° E. and is inclined from the vertical about 5° N.W. The inclination was only estimated. The bearings are true.
[76]. Both the types are referred to genus 1 of the augite-andesites, the olivine, when present, being quite insufficient to give a character to the rock. They however belong to different species according to the length of the felspar-lathes, which in the doleritic rocks averages ·2 mm. and in the other type ·08 mm.
[77]. It is pointed out on p. [5] that this name is wrongly applied in the Admiralty charts to Mount Mbatini, a mountain about three miles south of it.