Unknown freshwater species

Unknown freshwater species

Observation - Unknown freshwater species. Description: The unknown species that kind of looks like a horseshoecrab larvae is on the left near 7-8mm on the first photo. I have found this only twice at the same location when pond dipping but as we pond dip at the site quite regularly than it isn't common at thi

The unknown species that kind of looks like a horseshoecrab larvae is on the left near 7-8mm on the first photo. I have found this only twice at the same location when pond dipping but as we pond dip at the site quite regularly than it isn't common at this site.
Found in a narrow, shallow dyke at Ranworth Broads, Norfolk, England