STUDIES IN STELLAR STATISTICS. II. 105 
and so also are variables and stars having peculiar spectra. A cata- 
logue of these 804 stars is given in the memoir, containing the galactic 
eoordinates of the stars and also all the information that has been 
collected regarding them, such as spectral class, apparent magnitude, 
parallax ete. The distribution of the stars is graphically illustrated on 
the plates at the end of the memoir. Stereoscopical images, which will 
give a general view of the Galaxy of the B-stars in three dimensions, 
are in preparation. 
8) Finally the absolute velocity is calculated for those stars for 
whieh the proper motions as well as the radial velocities are known. 
The diseussion of these velocities leads to the result that the velocity 
surface of the Z-stars is an ellipsoid of revolution having the small 
axis perpendieular to the XY-plane of the Galaxy. The mean component 
velocity in the XY-plane amounts to 1.» Sir. and to 1.3 Sir. in the plane 
perpendicular to it, a result in close agreement with that of GYLLEN- 
BERG given in Meddelanden Ser. II N:o 13. 
Nova Acta Reg. Soc. Se. Ups., Ser. 4, Vol. 4. N. 7. Impr. '*/: 1916. 14 
