Calcite. 



This is in variable quantity, sometimes very plentiful. It 

 fills the angles of the rock, and is generally limited by sharply 

 defined linear boundaries. Its rhombohedral cleavages are 

 strongly marked. 



Quartz. 



This is everywhere clear. There seems to be two phases 

 in which it occurs. Its original condition is where it con- 

 tains tourmaline prisms, its secondary one where its 

 enclosures are needles of actinolite. 



Sphene. 



This is always granular, is abundant, and has probably 

 separated out during the alteration of the augite. 



The rock constituents seem to be present in about the 

 same proportions as those assigned by Zirkel to limurite, and 

 vary in the same manner. Thus he remarks that the axinite 

 is the basis of the rock, in which it appears now and again in 

 the form of large homogeneous crystals, while other parts of 

 the rock show augite and hornblende intergrown plentifully. 

 Professor Zirkel has been good enough to send to one of us 

 a sample of his limurite, and a copy of his paper " Limurit 

 aus der Vallee de Lesponne," from which we take the follow- 

 ing abstract of the occurrence of the rock : — " This rock was 

 first seen in the river bed of the Adour, but was found in 

 large blocks at the Bridge of G-erde. At last Count Limur 

 found it in situ as a rock covered with moss above the Cabin 

 Chiroulet in the valley of Lesponne. Nothing further is 

 known of it geologically beyond that in the upper parts of 

 this valley there is mica schist, with andalusite, garnet, 

 vesuviante, as well as tourmaline-bearing granite. The rock 

 is tough under the hammer. To the naked eye there are 

 visible dark violet-green individuals of pure, sometimes 

 striped, axinite, nearly an inch long sometimes ; also other 

 confused flakes of axinite, traversed by very fine deep grass- 

 green grains with other green parts which consist of an 

 aggregate of these grains. Here and there are large cavities 

 into which the sharp edges of axinite crystals protrude, or 

 small cavities where the green mineral forms little crystallised 

 heaps like warts, whose component individuals under the 

 magnifier look like little fassaites. Besides these are some 

 granules of clear quartz, specks of iron pyrites, and the fresh 

 rock effervesces in parts with HCL. Under the microscope 

 the following constituents are recognisable : — 



" 1. Axinite, with sections blue, grey-brown, to nearly 

 colourless, no particular cleavage. In coloured sections pleo- 



