134 ME. GARDINER AND PROF. REYNOLDS ON THE [May I909, 



patches of chlorite. Three sections were examined : (274) is a 

 normal felsite showing very clearly the imperfectly -spherulitic type 

 of ground-mass, which occurs so frequently in these rocks ; (273) is 

 an unusual type, containing a considerable amount of ilmenite. At 

 (4) the ground-mass shows a tendency to be spherulitic, little quartz 

 occurs, and plagioclase is present as well as orthoclase. Magnetite 

 is rather abundant, and there appears to be altered augite. 



Several isolated patches of felsite lie west of the main outcrop. 

 A small patch (284), lying south-west of the angle of Stream C, 

 has a coarser ground-mass than is usually noticed, full of little 

 grains of quartz. Apatite is present in some abundance. 



The felsite (38) intrusive among the tuffs of Mount Partry, which 

 may be mentioned here, contains numerous serpentinous pseudo- 

 morphs after pyroxene. Its specific gravity is 2*69. 



(5) Felsites between Stream C and the east-and-west 

 road south of Drumcoggy Rectory. — These rocks are very 

 variable : (14) is a red felsite, while (16) and (250), from near the 

 eastern border farther uorth, and (281) and (288) from near the 

 western border, are green felsite3 with rather conspicuous quartz- 

 crystals. Their microscopical appearance requires little description. 

 The ground-mass is generally of the imperfectly-spherulitic type. 

 In addition to the usual quartz and orthoclase-phenocrysts, altered 

 biotite (14) is sometimes met with ; and (281), a rock from the- 

 prominent felsite-crags east of Gortanalderg, contains abundant 

 serpentinous pseudomorphs apparently after pyroxene. Apatite is 

 fairly plentiful in this rock. Another rock (19) from this neigh- 

 bourhood has a specific gravity of 2*71, and contaius numerous 

 pseudomorphs in chlorite apparently after pyroxene. 



(6) Felsites between the east-and-west road south of 

 Drumcoggy Eectory and Stream F. — While in the main 

 these rocks are red felsites without prominent quartz-crystals, (146) 

 & (48) are grey, with fairly prominent quartz. The imperfectly- 

 spherulitic type of ground-mass is very well shown by (48), while 

 in (146) bands of quartz and felspar intergrown in an imperfectly 

 granophyric manner traverse the slide. 



Along Stream F the felsite shows some modifications excep- 

 tional in the district. At (44) the rock is full of thoroughly well- 

 rounded nodules which reach a diameter of a quarter of an inch. 

 They are all solid, and consist entirely of white crystalline quartz. 



Another rock (304) from the more easterly of the two felsite- 

 masses on the left bank of Stream F shows strong banding on 

 the weathered surface. In section it does not differ from the 

 majority of the felsites of the district, except for the unusually large 

 proportion of plagioclase present. 



(7) Felsite between Stream F and Shangort. — The 

 colour in hand-specimens shows various shades of green, grey, and 



