Found this quite easy apart from 7D (which I used a missing letters solver for as I had all the letters and it was the only one I was missing). And then it turned out to be a maths word I am very familiar with :/
Can't see where the Queen comes in in 11A?
What's with Manx (or is it just an anagrind) in 15D? If it is an anagrind what happened to the P? Oh, I guess it must mean "tailless", bit obscure that!