HALICLYSTUS AURICULA (rATHKe), AND OTHER MEDUS.E 283 



HALICLYSTUS AURICULA (RATHKE), AND 

 OTHER MEDUS/E IN THE FIRTH OF 

 FORTH. 



By William Evans, F.R.S.E. 



In a paper on the Fauna of the Forth Are», published 

 about eight years ago in the Proceedings of the Royal 

 Physical Society (vol, xvii., pt. i), I mentioned (p. 15) that in 

 1890 I had found, near North Berwick, a lucernarian, 

 believed to be Haliclystus auricula (Fab.). The specimen 

 having been lost, the identification was given, however, with 

 some reserve, and there appears to be no other record for 

 the area. It was, therefore, a source of no little satisfaction 

 to me when on ist August this year (1916) my son, 

 W. Edgar Evans, found another example in the same 

 neighbourhood. It was adhering to a sea-weed, Chondrus 

 crispus, growing on the rocks at low-water mark (spring tide) 

 a few hundred yards west of the harbour. North Berwick. 

 It was brought home alive, but survived only two or three 

 days. When expanded, its diameter, inclusive of the arms, 

 on the tips of which the tentacles are clustered, was about 

 18 mm., and 10 to 12 mm. at the intervening spaces. The 

 groups of tentacles are eight in number, and the number of 

 tentacles in each is about 50, except in the case of a rather 

 stunted arm which bears scarcely 40. The stunted arm is 

 placed close to one of the normal ones, but otherwise the 

 arms are fairly equidistant though there is a tendency to an 

 approximation in pairs. On the margin of each sinus 

 between the arms there is a distinct " statorhab," or anchor. 

 In life, the colour was a pinkish brown with the tips of the 

 tentacles yellowish. 



The presence of the anchors alone proves the specimen 

 to be a Haliclystus and not a Luccrnaria (as now restricted), 

 but it is not so easy to decide what the specific name should 

 be — whether auricula or octoradiatus. Writing in 1863 in 

 the Journal of the Boston Society of Natural History^ James 

 Clark considered, as likewise did Haeckel in 1879 {System 

 Medusce), that there are two forms, one having the arms 

 approximated in pairs, and 100 to 120 tentacles in each group 

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