104 Canadian Record of Science. 



mineral, and occupies cracks in the garnet a little more 

 frequently, but, as before, the constituents tend to lie 

 parallel rather than radially. One or two of the diopsides 

 show line oscillatory twinning. The cracks are occupied 

 with calcite or some altered carbonate. There is no real 

 difference between this eclogite and the last-named one. 



Eclogite Boidders icitliout Diamonds. 



3. Part of a boulder, which must have been about a 

 foot in diameter. — In macroscopic aspect it presents a 

 general resemblance to the rocks described above, with, 

 however, the possibility of a second green constituent. 

 This is not confirmed on microscopic examination. The 

 rock consists, practically, of pyrope and diopside, as 

 already described, except that the negative crystals are 

 .rather unusually conspicuous in the latter. Into the 

 details of these, as the point seems not to have any 

 bearing on the present investigation, I do not purpose to 

 enter. 



4. A fragment, more irregular in form than the others, 

 measures, very roughly, about 7 in. by 4| in. by 3-| in. 

 It retains a good piece of the outer surface, which, thougli 

 now a little corroded, was once smooth. The rock, which 

 is rather decomposed and crumbly, consists chiefly of 

 three minerals ; garnet, not quite so large, paler and more 

 pink in colour than the last-named ; an emerald green 

 pyroxene, and a yellowish or greenish grey, platy to 

 fibrous mineral, suggestive of a second more altered 

 pyroxene. In thin slices the paler and pinker tint of the 

 garnet is very perceptible, as well as the tendency to a 

 rude and generally parallel cleavage. But we find in it, 

 under the microscope, a few microlithic enclosures, of 

 an apparently colourless mineral, which occurs in long- 

 prisms crossed at about 70° by an occasional transverse 

 cleavage, and extinguishing at an angle of about 26° with 

 the longer edge. Many of the cracks exhibit slight de- 



