330 Southern Cross. 



similar to those in the basalts, are seen in a groundmass of felspar 

 laths, magnetic grains and ragged shreds of dull green tegirine- 

 augite. 



These rocks certainly have very similar characters to those of the 

 phonolitic rocks from Africa, but they also present perhaps even 

 more striking resemblances to rocks from a nearer locality, viz., the 

 Dunedin District, New Zealand. Phonolitic rocks from the top of 

 Flagstaff' Hill, Dunedin, in the Museum Collection, show phenocrysts 

 of anorthoclase, partially reabsorbed basaltic hornblende, and pale 

 green augites in a ground-mass of felspar laths and feathery tufts of 

 .Tgirine-augite, as in the case of the rocks described above ; pheno- 

 crysts of olivine, surrounded by a^girine-augite, are also generally 

 present in small amount. These rocks which occur with basalts are 

 of early Tertiary age, and are, in fact, associated with Palicozoic 

 rocks, consisting of clay-slates and schists, as in the case of these 

 Antarctic rocks. 



A pumiceous rock, found by Mr. Bernacchi on the top of Cape 

 Adare, probably belongs to the same " kenyte " series. It consists of 

 a highly vesicular, nearly colourless glass, crowded with gas-pores and 

 dark, dusty inclusions, and containing phenocrysts of large, much 

 corroded anorthoclase felspars, pleochroic (pale yellow to pale green) 

 diopside-like augites, and, very sparingly, olivine and basaltic 

 hornblende. 



A pale rhyolitic-looking rock, found by Lieutenant Colbeck at 

 Wood Bay, Newnes Land, is of a somewhat similar character, but 

 less glassy. The same phenocrysts of anorthoclase, together with 

 olivine and pale green augite in very small amount, occur in a very 

 fine grained base, consisting of minute felspar laths showing flow 

 structure. 



A tuff from Protection Cove, near the junction of the basalt with 

 the slate, contains, besides fragments of basalt, also small fragments 

 of a glassy rock speckled with magnetite ; it shows in some cases 

 perlitic structure, and also rarely phenocrysts of felspar and a pale 

 greenish-yellow augite (see PI. LIIL, fig. 6). 



CONCLUSIONS. 



The granite rocks found as boulders on Cape Adare, together with 

 mica-schists and gneisses, such as were dredged by the ' Challenger,' 

 prol)ably constitute the basement rocks of Victoria Land, underlying 

 the slate. 



