6 Scientific Proceedings, Royal Dublin Society. 



from St. Yaast la Hogue (Manche, N. France), and for which he 

 constituted the new genus Xanthiopus ; his definition of this genus 

 agrees so exactly with that of Halcampa, as defined by Grosse, that 

 there is no doubt they are synonymous, and the latter has the pre- 

 cedence. The two species are yellowish in colour, and were found 

 in the small chinks in the granitic rocks at extreme low water. 



Halcampa {Xanthiopus) bilateralis. — The tentacles corresponding 

 to the ends of the mouth are differently formed and without trans- 

 verse bands, as in the other ten, and which bear two yellow trans- 

 verse bands. All the tentacles are continued over the oral disc as 

 triangular swellings to the opening of the mouth. About 40 mm. 

 long. 



H. (X.) vittatus. — All the twelve tentacles are similarly formed, 

 with four yellow transverse bands ; they do not run over the oral 

 disc to the mouth. Mouth in the middle of a small, conical, raised, 

 yellow ring. About 20 mm. long. 



These two forms are undoubtedly the same species. Andres, 

 also, is of the same opinion ; but he, contrary to the British rules 

 of Zoological nomenclature, re-names the species as H. kefersteini, 

 consisting of " var. a vittata ; tentacles equal ; small size ; and var. 

 (5. bilateralis; Glonidial tentacles different from others by lacking 

 the annulations ; larger size." 



The pale colour and different appearance of the gonidial 

 tentacles of the first species is not unfrequently met with in 

 many of our British sea-anemones (e. g. Tealia crassicomis, Miill., 

 Actinoloba dianthus, Ellis, and Heliactis bellis, Ell. and Sol.). The 

 only other distinctions between the two species are different num- 

 ber of yellow bands on the tentacles, and the presence or absence 

 of distinct radii on the oral disc — characters too slight to alone 

 constitute specific distinctness. The conclusion at which we must 

 arrive at is, that these two forms are merely varieties of H. chry- 

 santhellum. 



Dr. Ed. Grube found H. chrysanfelliim (sic) at Eoscoff, buried 

 in the sand at low water. He states that it only occurs in a single 

 zone. "A few steps nearer the sea and one no longer finds it. 

 These and the nearly allied Edwardsias are so completely hidden 

 in the sand that their presence is not betrayed." He describes it 

 as a perfectly white polyp, of the thickness of a swan's quill, with 

 twelve short tentacles, and a single black point between each. The 



