Last week, I put up an ID challenge that I thought would be relatively simple but which was apparently more difficult. Does that mean that today's challenge, which I think is damn near impossible, is really quite simple?
As a clue, the animal shown lives in fresh water. The scale bar represents 1 mm for all figures except fig. 73, for which it represents 0.5 mm. Attribution to follow.
The last few ID challenges have been getting good responses, so I think it may be time to up the stakes a little. Like Alex Wild does for his challenges, I'm going to award points for correct answers. But unlike Alex, I'm not going to have any set rules about how those points are divvied up. Basically, three points will be awarded to the person who gets the closest to the correct identification. Bonus points (one or two points) may be awarded to up to two less precise answers that contribute to the correct identification (say, if someone identifies the family but not the species, or draws attention to a significant diagnostic feature).
But that's not all there is to it, because I'm also going to take a certain degree of inspiration in awarding points from QI. If you want to win points, but find that someone else has already correctly identified the species, don't despair: if you can provide a better answer than the one they gave, you may be able to steal their three-point spot off them! Examples of better answers would be if you provide a better explanation of the diagnostic features, or if you tell me something really interesting about the organism in question. If you do bump the previous leader from the top spot, they'll be knocked down to the two-point position. Even if you don't successfully knock down the leader, you may be able to get the two-point or one-point position yourself. Unless, of course, someone else pushes you out in turn. Also, I should note that all three point-spots are awarded entirely at my discretion: if there are not suitable answers, I may not award one or more of the point slots.
The first person to get a total of ten or more points from successive Name the Bug posts will win the first round. I'm still deciding what exactly you'll win; my current inclination is to give you a choice between requesting a post on the topic of your choice, or of being given a guest post on Catalogue of Organisms.
As this is the first round, I'll be generous in my judgement of which comments are worthy of the points (so please have a go—after all, I'd look a right twit if I didn't get to award any points in the first challenge!) Let battle commence!