(Alder & Hancock, 1844)
Known from a very few records [less than 6] from the British Isles and Atlantic coast of France. Reported in Forum from Norway.
Locality: Vikaneset, Kristiansund, 6-7 metres, Norway, Atalntic, 28 April 2007, Rocky, Kelp forest. Length: Ca. 10 mm. Photographer: Christian Skauge.
Proctonotus mucroniferus has seldom been recorded, and little is known of its anatomy, and even less about its biology. As far as I know its radular morphology is still unknown. Thompson & Brown (1984) summarise the available information.
It is a translucent to transparent brown with scattered darker brown patches. It is similar to Janolus hyalinus in shape and colour but lacks the crest [or 'caruncle'] between the rhinophores. The rhinophores are wrinled and nodulose. This species has a number of rows of cerata around the edge of the body, including the anterior end. The cerata are somewhat nodulose and the tip is truncated and button-like. There is a single duct of the digestive gland running into each ceras, except those at the anterior end of the body.
Alder, J. and Hancock, A. (1844) Description of a new genus of Nudibranchiate Mollusca, with some new species of Eolis. Annals and Magazine of Natural History 13: 161-166.
Thompson, T. E. and Brown, G. H. (1984) Biology of Opisthobranch Molluscs Vol 2. 229 pp. 41 Pls. Ray Society 156.
Rudman, W.B., 2007 (May 8) Proctonotus mucroniferus (Alder & Hancock, 1844). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/procmucr