Pachymatisma johnstonia. Site: Ruecallan, Rathlin Island
 Pachymatisma johnstonia. Event number: 19850702/01. Site: Ruecallan, Rathlin Island. 1985-07-02. Photograph © Ulster Museum. (6/32) 
 Ulster Museum (2026). Photograph of Pachymatisma johnstonia. Site: Ruecallan, Rathlin Island. [In] Marine Biodiversity Data Portal - NI.
https://habitas.org/mbdp/sitephoto.php?item=niss_10552.jpg. Accessed on 2026-11-04