The specimens from the Cape R oyds kenyte are small fragments, from which it is impos- 

 sible to infer the size of the whole inclusion. They are of moderate grain and are more 

 compact than the sanidinites of Mount Cis. In section they show large, somewhat 

 rounded phenocrysts of anorthoclase in a ground-mass of radially disposed microlites, 

 which from their straight extinction appear to be sanidine(Fig. 1, PI. II). A pale brown 

 glass is very abundant, and from its occurrence in irregular patches and not in the 

 interstices of the rock structure it appears to result from remelting of part of the rock. 

 I rregular grains of magnetite are abundant within the phenocrysts and in the ground-mass. 

 A clear biotite occurs sparingly in large plates and also in clusters around the mag- 

 netite. On the exterior of the inclusion, the microlitic character disappears; large 

 and small rounded plates of anorthoclase with a little brown augite and small magnetite 

 grains form an irregular mosaic like that of a sandstone (Fig. 2, PI. II). 



The inclusion in the kenyte of Inaccessible Island is a spherical mass about 5 cm. in 

 diameter. It is only slightly miarolitic, and consists of large platy twinned felspars 

 in a brownish felspathic matrix. In section the large felspars are seen to be andesine 

 with both Carlsbad and albite twins, and in opposition to those of the ground-mass 

 they are clear and glassy. The latter have a peculiar stippled appearance owing 

 to the separation of opaque matter (limonite) along both sets of cleavage planes. 

 They show only Carlsbad twins, and are to be referred to sanidine on account of 

 their refractive indices, but they occasionally contain clear kernels of anorthoclase. 

 For the most part they have stout columnar habit with an approach to orthophyric 

 arrangement, but there are smaller miarolitic areas partially filled by much more 

 slender microUtes together with iron ores. Magnetite is abundant both as enclosures 

 in the felspars and in the interstices of the ground-mass. With it is associated a 

 very little biotite, and a greater amount of a yellowish green mineral of high 

 refractive index. 



The inclusion in the erratic black kenyte found at Cape Royds is a biotite microsani- 

 dinite. It contains large pseudoporphyritic plates of anorthoclase lying in a matrix 

 of small quadrate prisms of sanidine, anorthoclase, oligoclase, and glass. Well-shaped 

 large and small crystals of magnetite and more or less rounded plates of biotite are 

 abundant. 



The inclusion in the kenyte of Tent Island is a large mass 8x5x6 cm. The hand- 

 specimen shows large platy felspars with a miarolitic brownish red cement, in the midst 

 of which iridescent black crystals of olivine may be recognised. The large felspars 

 are zoned and twinned in a complex manner (Fig. 3, PI. II) and prove to belong to oligo- 



