[78-L] Columbia's subsidiary labels

[Harold Aherne]

Several interesting phenomena occur with these labels in the later years of
their existence, and I wonder if anyone has comments on them:
 
Around late 1930 or early 1931, Harmony and Velvet Tone finally got out of 
step in their numbering sequences (i.e. the catalogue numbers on VT were
no longer automatically 1000 higher that Harmony's), but I've never heard
anything definite about Diva.  Did that label follow either of its siblings
in numerical sequences?
 
Several recordings in mid-late 1930 appeared only on Clarion, including 
(by my count) three Annette Hanshaw sides and probably additional
recordings by other artists. Was there any special reason for this, aside 
from making the new label stand out just a bit? 
 
Also in 1930 there was a race series that appeared only on VT and Diva.
Anyone know how many issues and which artists appeared in it? I know that
Eva Taylor and Katherine Henderson were two, but I haven't yet come across
listings for others.
 
-Harold