There were two small species that have not yet been identified to genus level. The one in the photographs above are under identification investigation. I am beginning with the Platycheirus genus. It is a species very frequently seen. Note that the antennae are black in this small hoverfly. The scutellum is dark brown/black as well.

 The consensus is that it is Platycheirus albimanus. These identifications were made on the Diptera Forum.

I suppose the only other possibility is Platycheirus scutatus, but I would also opt for Platycheirus albimanus, as it is slightly thicker in the abdomen and the spots are at best bronzy rather than dull orange. Also I would guess that this specimen is not dusted on the frons, although it is a bit difficult to be sure. Time of year makes me lean a bit more towards Platycheirus albimanus than Platycheirus scutatus too.

I found it useful when teaching myself Platycheirus several years ago to draw up a grid with the species names across the top and a list of external features including colour of each antennae and leg segment and basic notes on habitat and flight period. I found this easier to use as a raw beginner than the keys initially, as I could draw in information as I acquired it, rather than get stuck on a key couplet.