Thank you so much for these photos of the pages of the first volume of Russell’s monograph with the account of Craspedacusta sowerbii (=C. sowerbyi). (Looking forward to reading this at home, currently on a NYC subway train with intermittent connectivity!)

That would be much appreciated, Ian, thank you very much. Many thanks also for the clarification about the two volumes.
A friend who lives near Green-Wood Cemetery posted this @inaturalist.bsky.social observation of Craspedacusta sowerbii from 25 October 2025:
www.inaturalist.org/observations...

That’s really interesting, thanks! Vol II is accessible via the @archive.org (archive.org/details/medu...) but unfortunately not Vol I. Here in Brooklyn, New York, there have been reports of the species since quite recently, in the Sylvan Water in Green-Wood Cemetery.

Does the first volume of Russell’s The Medusae of the British Isles include the so-called Common Freshwater Jellyfish (Craspedacusta sowerbii) (Hydrozoa: Limnomedusae)?