NEW-ZEALAND ACTINIARIA. 535 



C Haddoni (the height being about 13 mm., and the diameter of 

 the disc about 8 mm.), less variable in form, and, unlike that 

 species, it appears not to increase by budding, all the specimens 

 which have been found being solitary. 



Actinia tenebeosa, n. sp. 



Column cylindrical, short ; body-wall smooth, without warts, 

 extending beyond the disc and forming a well-developed collar, 

 within which the marginal spherules lie hidden ; marginal 

 spherules numerous, bluish white ; tentacles conical, in three 

 indistinct, crowded rows. Height of column about 27 mm. ; 

 diameter of disc about 40 mm.; length of tentacles about 

 15 mm. 



Hab. On rocks, just above high-water mark, in the neighbour- 

 hood of Wellington ; abundant. Mr. T. M. Grant informs me 

 that it also occurs freely in Queen Charlotte Sound. 



This species is a good example of the effect of light on the 

 colour of animals. Full-grown individuals in situations well 

 exposed to the rays of the sun have the column greenish or 

 brownish black, and the disc and tentacles dusky crimson, while 

 those on the undersides of overhanging stones are reddish brown 

 or crimson, the depth of colour varying according to the amount 

 of light which reaches them. Specimens on the vertical sides of 

 rocks (their favourite habitat) often have a patch of reddish 

 brown on the side turned away from the light. I found a 

 specimen under a large stone which had evidently never been in 

 the light : the whole animal was yellowish white with a slightly 

 greenish tinge. 



This is a fine species for the investigation of the development 

 of Actinians, for large specimens usually have a number of young 

 ones within them in diifferent stages of development. The young 

 are retained in the body of the parent till they attain a 

 considerable size. 



This is the southern representative of the European species 

 Actinia equina. It forms another extremely interesting example 

 of the law discovered by the late Prof. Edward Forbes, the 

 great pioneer of the distribution of marine animals, that " similar 

 species, to which the term representative is mutually applied, 

 appear in areas distant from each other, but under the influence 

 of similar physical conditions " (Nat. Hist, of the Europenn Seas, 

 p. 8). It appears that this law (if such it may be called) was also 



38* 



