138 



ACTINIARIA 



Actinia rubra, Forsk. , Sars 1835, P- 3' i&53> P- I2 - 

 PAclinia cari delle Chiaje, Arndt 1912, p. 123. 



A more complete list of synonyms and literature is given by Andres 1883 and Pax 1908, p. 467. 



1 think however that A. rufa of Miiller is not this species but rather a young Metridium dianthus. A. cari 

 is probably a distinct species. 



Diagnosis: Nematocysts of the column 14 19 x 1,5 //, those of the acrorhagi 41 58 (65) x 2,5 

 ^ (i, those of the tentacles 19 24 X 1,5 u and those of the actinopharynx 18 29 X 1,5 (2) p. Spirocysts 

 of the tentacles 14 X i 29 X 2 //. Acrorhagi spherical with an aperture, in variable number (commonly 

 24 teste Andres). Sphincter with low folds especially in its proximal and distal parts, the folds however 

 rather much ramificated. Outer parts of the oral disc with tentacles in number to about 192. Inner tentacles 

 a little longer than the outer ones. Pairs of mesenteries to about 96. Longitudinal muscles in the outer parts 

 of the mesenteries very weak, in the inner forming rather weak diffuse pennons. Parieto-basilar muscles 

 distinctly definite, broad, expanding over almost the whole length of the column. Basilar muscles strong. 

 Development of the embryos in the coelenteric cavity. 



Colour very variable. Pax (1907, 1920) distinguished two main forms i) forma rubra: Red or scarlet- 

 red. Acrorhagi blue. Sometimes blue annulus at the base of the column (the Bergen-specimens lack this an- 

 nulus teste Appellof), 2) forma viridis: Column olive grey to grass-green, acrorhagi bluish-green, annulus 

 blue. Sars states that liver-coloured specimens (forma hepatica Gosse?) are common in Ogsfiord and at Ham- 

 merfest. Gosse and Andres described several varieties of colour in this species. 



Dimensions: in expanded state: breadth to about 7 cm, height to 5cm, length of the tentacles 

 to 1,5 cm (Andres). 



Occurrence. Norway: The West coast at least from Stavanger (teste Brinkman) to Hamnier- 



fest. Bergen (teste Sars, Appellof), S01svig (teste Schulze and Sars), 

 Vaagsfiord, Ulvesund, outer Nordfiord (teste Grieg), Molde (teste Arndt, 

 A. cari?). Nordland Finmark toVadso (teste Danielssen), Ogsfiord, Ham- 

 merfest (teste Sars). 

 Kola peninsula. Pala Guba (teste Pax). 



Shetland Isl. Balta sound (Hammarsten, i sp.) (teste Norman). 

 ? Denmark. Great Belt, Romso (teste M obi us, probably not this species). 



Further Distribution: North Sea, coast of Germany (Helgoland and other localities), Great 

 Britain and Ireland. W. coast of Europe, W. coast of Africa to Cape Verd Isl., Madeira, Canary Isl., Medi- 

 terranean, Black Sea, Sea of Asov. --on exposed rocks from half-tide to low-water mark (Gosse). 



The exterior aspect of this species has been described by several authors, likewise the anatomy 

 especially by Jordan (1880), Simon (1892) and Pax (1920). I will here only add some notes. I have exa- 

 mined two species, one from the Shetland Islands (height 0,7 cm, breadth 1,5 cm) another from Naples (height 



2 cm, breadth 5 cm), as regards the stinging capsules. Though the specimens were very different in size the 

 stinging capsules were of about the same size in them both. The nematocysts of the column were very sparse, 

 14 19 X 1,5 n resp. 14- 16 x 1,5 fi, those of the tentacles not numerous 19 22 X i,5// resp. 19 24 X 



