The Spectator 2317-370 By Doc - July 2017

[Matakari]

Thanks for answers to the following, please! Rationale will be appreciated if possible.

ACROSS:
19 Horizontal figure showing spirit in new dance ( 7 ): D - C ---N
39 The BBC's family members (7 ): A-I----

DOWN:
7 Originally African dog tailless, at backwater ( 6 ): SLO---
21 eying one German in stud ( 6 ): --EI--

[Neveracrossword]

21 Seeing, eying. Seg = stud (on shoes, for example) with Ein, one in German, inside.

[Neveracrossword]

39 Aunties - Auntie is a familiar term for the BBC, so Auntie's - and Aunties, family members.

[aelmpvw]

21 se(ein)g
seg = stud, ein = one

[Neveracrossword]

19 Decagon, horizontal figure - anagram of Dance and Go/spirit.

[donny48]

7slough

[donny48]

7 sloughi name of African dog breed minus tail = lough = backwater

[hankir]

I am now stuck with unclued 17d and 22a.
I think the first letters of each will help.

Thanks.

[hankir]

I now have all the unclued.
Three British names were new to me.