90 G Canadian Arctic Expedition, 1913-1918 



remarkable variations of this kind occur in Sagartia venusta, S. miniata, and 

 other allied species. (See Dixon, Proc. Boyal Dublin Soc., Vol. VI, pp. 136-142, 



1888). 



Sub-family SAGARTIN^) Verrill, 1868. 



Sagartian actinians having a flexible column wall, without a closely adherent 

 epidermal coating, with cinclidse, with or without adhesive suckers, without 

 thickened tubercles or verrucae. 



Metridium dianthus (Ellis) Oken. 



Actinia dianthus ELLIS, Phil. Trans., Vol. 47, p. 428, PI. XIX, fig. 67, 1767. 

 ELLIS and SOLANDER, Hist. Zoophytes, p. 7, 1786; also many later writers. 



Metridium dianthus OKEN, Lehrb., Vol. Ill, p. 450, 1815; H. M.-EDWARD and 

 HAIME, Corrall., Vol. 1, p. 253, 1857; McMuRRiCH, Annals New York 

 Acad. of Science, Vol. XIV, No. 1, p. 3, pi. 1, figs. 1-5, 1901. (Sections). 



Actinoloba dianthus (BLAINVILLE) GOSSE, Actinologia Brit., p. 12, pi. I, fig. 1, 

 1860. ANDRES, Attinie, p. 133, fig. 15 (after GOSSE). 



Metridium marginatum (LES.) H. M.-EDWARD, op. cit., p. 234, 1857; VERRILL, 

 Revision Polyps E. Coast, pp. 22-24, 1864, and most other American 

 writers formerly. 



Metridium fimbriatum VERRILL, Proc. Essex Inst., Vol. IV, p. 150, 1865, des- 

 cribed from Calif ornian speciemns. 



Metridium senile McMuRRiCH, Trans. Royal Soc., Canada, Vol. IV, section 4, 

 p. 60, 1910, (not Actinia senilis LINN., 1767, nor Priapus sinilis LINV.. 

 1761). 



Plate XXVI; Fig. 2. Plate XXXI; Fig. 6. 



This species is readily distinguished by its smooth column, well defined 

 parapet, widely expanded oral disk, which in well grown specimens when ex- 

 panded is thrown into a number of marginal frills or wavy lobes covered with 

 large numbers of small and rather slender tentacles. The outer ones much 

 smaller than the inner ones. 



When very large it may have about a thousand tentacles, and a corres- 

 ponding number of mesenterial pairs, and abundant white acontia, which 

 are readily emitted from scattered cinclidaB when the creature is roughly handled, 

 and also from the mouth. 



It is very changeable in form while living. In full expansion it may be 

 much higher than broad, or its height may be less than its diameter. The 

 disk is usually much wider than the column. Its disk and tentacles can be 

 completely invected together with the upper part of the column, and then 

 it may have a hemispherical form or become even more depressed in form. 



Its colours on the New England coast are very variable, rarely white or 

 blotched with white. Most frequently its colour is dull yellowish brown, dark 

 olive-colour, or chestnut brown to umber brown and often blotched or streaked 

 with lighter colours; sometimes it is pale buff, salmon-colour or flesh-colour, 

 rarely brick-red. The tentacles are usually paler or even white. 



Professor W. R. Coe, who was one of the naturalists on the Harriman Alaska 

 Expedition, tells me that at Victoria, British Columbia, he found the piles 

 of the wharves, at low tide, entirely covered with large examples of this species, 

 which were, when in expansion, white or nearly so. 



It is capable of reproduction asexually in several ways: by longitudinal 

 fission; by budding from near the base or rarely elsewhere; and by breaking 

 off fragments from the edge of the expanded basal disk, each of these pieces 

 developing into a young one in a short time. This last is a common mode of 

 increase. 



