I. From the most westerly quarry. Rock comparatively unaltered. (PHILLIPS). 

 II. From the most easterly quarry. Rock considerably altered ; felspars almost 



completely kaoliiiized. (PHILLIPS). 

 lit. From Messrs. BUNDEIT & Go's eastern quarry. Rock more altered than the 



last. (PHILLIPS). 



IV. Grey vein, from the same quarry as No. I. (WALLER). 

 V. " Quart/-norite " from the Vildarthal near Klausen. (TELLER and VON JOHN.) 



Mr. PHILLIPS' specimens were selected to illustrate progressive 

 metamorphism by surface agencies. The analyses prove that this 

 metamorphism is accompanied by the removal of lime and magnesia 

 and by the formation of hydrated silicates (the water in No. III. was 

 found to be combined ; not hygrometric). The two last analyses must 

 be compared with the first analysis by Mr. PHILLIPS ; not with the 

 second and third which represent altered rocks. 



Mr. WARD has described several rocks occurring in the northern 

 part of the Lake District under the term diorite. The Little Knott 

 rock has already been alluded to (see ante, p. 100). Quartz-diorites 

 occur, according to Mr. WARD, at Seathwaite How, Hindscarth, and 

 Burtress Comb. These rocks appear to be all very much altered and 

 not very typical of their class. A specimen from Seathwaite How 

 collected by the author is a line-grained greyish rock mainly composed 

 of turbid felspar with which is associated a little quartz possibly of 

 secondary origin. The original ferro-magnesian constituents appear to 

 have been a pale augite and biotite. They are more or less replaced 

 by green decomposition products, possibly in part uralitic. Ragged plates 

 and skeletons of iron-ore are scattered through the slide. The ferro- 

 magnesian constituents arc completely subordinate to the felspathic 

 constituents and the rock appears to belong to the leucophyre division 

 of the diabases rather than to the diorites. 



Rocks of a dioritic character occur in the Lizard peninsula. They 

 are present as veins in the gabbro at Pen Voose and they also 

 constitute a part of the banded gneissic series which Prof. BONNET 

 proposed to call the granulitic series. This series consists principally of 

 two types of rock a diorite and a fine-grained granite. In some places 

 the two types may be seen veining each other after the manner of 

 igneous rocks ; in others they occur in parallel bands, sometimes puckered, 

 as is common in banded gneisses. Parallel structure (foliation) is often 

 seen in the arrangement of the constituents when the rocks themselves 

 exhibit a parallel structure on the large scale. To what extent the parallel 

 structure is due to movements posterior to consolidation has not as yet 

 been determined. The relation of the dioritic and granitic rocks to the 

 gabbros and serpentines is also involved in some obscurity. They are in 

 part at any rate of later date for they occur as veins in the gabbro and 

 sometimes contain included fragments of that rock. 



The constituents of the dioritic rocks are felspar, biotite, green horn- 

 blende, sphene, iron-ores and apatite. The felspar is sometimes turbid and 

 sometimes fresh. The fresh felspar in the massive (non-foliated) rocks 

 usually shows multiple twinning, but in the rocks possessing more or less 



