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one another is obvious, but in the light rock, where it borders 

 on the dark, lies what seems to be a fragment of a foreign 

 gabbro-like rock. A mass enclosed in another sample must 

 derive from some almost completely assimilated fragment of a 

 foreign rock; in it we find several large grains of garnet to- 

 gether with large felspar individuals. The surrounding mass 

 is curious, partly micropegmatitic, partly consisting of large 

 individuals which are perfoliated, with a certain regularity, by 

 a fine powder and, moreover, embrace thin needles or scales 

 which appear to consist of chlorite. 



A curious enclosure, met with in another slide, consists 

 of a single individual, some centimetres in length, of a colour- 

 less mineral, entirely intergrown with biotite, yet without cry- 

 stallographic orientation. Nepheline it is not, and I can only 

 class this mineral as orthoclase, though with uncertainty. 



Of a somewhat different type is another of the samples 

 collected. The main mass looks more basic and externally forms 

 a transition to the group of rocks immediately following. In it 

 lie numerous, rounded balls or pebbles of red porphyry, but also 

 of other rocks, among which are such as recall in appearance 

 clay-slate. One is inclined to call the rock a volcanic con- 

 glomerate. Microscopically, the main mass shows nothing 

 remarkable, save that it is more disintegrated than usual; 

 this holds good especially of the felspar phenocrysts, which 

 are usually entirely transformed. There are moreover mica, 

 generally converted into chlorite, and a little quartz. The por- 

 phyry "pebbles" are of several types: some contain quartz, 

 some do not; biotite, more or less well preserved, is almost 

 always present, and the felspar is strongly disintegrated. In 

 one piece there are some peculiar pseudomorphs, forming in 

 the transverse section very pointed rhombohedra; I cannot 

 recall any certain interpretation, but possibly these were am- 

 phiboles that appeared in an unusual crystalline form. Interesting 

 is the ground-mass, which must have been very compact, but 



