Thanks, Alex!
The one I thought was obscure was 14d, and it might have been better if I'd put 'Smith's French ringlet'. I thought the etymological origins of that name (the answer) might not be generally known. Clearly, I underestimated you!
I have a confession to make, too. I was experimenting with a programme called 'Puzzle Workshop' that I bought here:
http://www.archersoftware.co.uk/crossword/index.htm
for £12.
I imported butterfly-related words from my website (actually, I turned the checklist of butterflies I had seen into a single column, one word per column, raw text file and imported that), chose my grid and clicked 'generate'. The programme supplements the imported file with its own list of 60 000 words but chooses the imported words where possible.
Obviously, I wrote the clues myself! But I've often spent hours and hours just on filling the grids in the past and I thought a programme must exist to do this faster.
Sorry - I'm not quite as clever as you thought!
Guy
