Pachymatisma johnstonia. Site: Archway, The North Wall, Rathlin Island
 Pachymatisma johnstonia. Event number: 20240520/01. Site: Archway, The North Wall, Rathlin Island. 2024-05-20. Photograph © Erling Svensen. (19/88) 
 Erling Svensen (2026). Photograph of Pachymatisma johnstonia. Site: Archway, The North Wall, Rathlin Island. [In] Marine Biodiversity Data Portal - NI.
https://habitas.org/mbdp/sitephoto.php?item=es2024_073.jpg. Accessed on 2026-11-03