61 



in regular orientation implanted on the faces of the third pina- 

 coid of the eudidymite. The orientation is such that the longi- 

 tudinal direction of the epididymite needles is parallel to the 

 edge (1(1:001) or (ill: 001) on the eudidymite, and the 

 third pinacoids (OOl) of the two minerals are parallel. 



13. Epididymite. 



Of this mineral only very little material has hitherto been 

 known. In the Lützen collection a very small quantity of 

 it was found, and the crystals on which accurate measurements 

 could be made, were very diminutive in size. The scanty supply 

 of suitable material was also the reason why the optical investi- 

 gation of the mineral could not be performed with the desirable 

 accuracy. 



The find of epididymite made afterwards near Langesund 

 in Norway was, it is true, richer in as much as a larger number 

 of specimens were met with there. But the single crystals on 

 these specimens were smaller still than those from Greenland. 

 An accurate optical investigation according to usual methods 

 could not, therefore , be made on them any more than on the 

 first-mentioned material. There has, consequently, been a 

 certain deficiency in our knowledge of this mineral. 



The epididymite material which I have collected on Nar- 

 sarsuk is very rich, various, and excellent in every respect. 

 Epididymite is, indeed, one of the most common minerals of 

 the place. It was found at different localities in the area and 

 with very varying associations. It is always crystallized, and the 

 crystals vary in size from such as can be seen only with the 

 aid of a magnifying glass to individuals and groups of more 

 than half a decimetre in extent. Also in form the crystals 

 differ considerably from one another. Among the different 

 shapes three crystal types can easily be distinguished , a de- 

 scription of which is given here. 



