Peter, you've got to get down there, pry one off and check it out for me. Might
you have a digital camera? Or a magnifying glass?
I'm very curious ;-)

Have you ever seen snail eggs? They are transparent and are glommed onto
things, like liners. They could look like a transparent leech.
The only other transparent things I've seen were, what I think, hapless
caddisfly larva deposited by their mother with no pebbles and sticks with which
to build their cocoon. They eventually wound bits of string algae around
themselves.

This is what I know about leeches.
Most eat vegitative and decaying matter. Handy to have around. I've kept them
inside to keep glass ponds clean. A few suck blood but they look like blood
suckers.
You can always test your leech by offering it yourself (not recommended) or a
piece of raw liver.
There are also flatworms who look like leeches.
If you look closely you can see two eyes on the top of their heads, or front
ends, as opposed to their tail ends.

Leeches can be caught, if they are the carnivorous kind, by suspending a
strawberry basket in the pond with some raw liver bait.




kathy :-)
algae primer
http://hometown.aol.com/ka30p/myhomepage/garden.html