Another oddity in this puzzle is: why are there numbers in the top-left, top-right and bottom-left squares? It's not as though there are clues numbered 1, 9 or 43.
I found that, once I had solved 8d, 13d and 14d, giving a pretty clear indication of what 17a is, the rest fell into place very quickly. In a week when the Listener puzzle is so completely beyond me - never mind the clues; I can't understand the instructions! - I should have liked the Speccie to give my little grey cells a bit more of a work-out.