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. Royal Dublin Soc, Vol. VI, pp. 136-142, 



1888). 



Sub-family SAGARTIN^ VerriU, 1868. 



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

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

 thickened tubercles or verrucse. 



Metridium dianthus (Ellis) Oken. 



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

 Ellls and Solandee, Hist. Zoophytes, p. 7, 1780; also many later writers. 



Metridium diantlivs Oken, Lehrb., Vol. Ill, p. 450, 181.5; H. M.-Edwaed and 

 Haime, CorralL, Vol. 1, p. 253, 1857; McMueeich, Annals New York 

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



Actinoloha dianthus (Blainville) Gosse, Actinologia Brit., p. 12, pi. I, fig. 1, 

 1860. Andres, Attinie, p. 133, fig. 15 (after Gosse). 



Metridium marginatum (LeS.) H. ^NI. -Edward, op. cit., p. 234, 1857; Vehrill, 

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

 writers formerly. 



Aletridium ji)uliriatum Veerill, Proc. Essex Inst., Vol. IV, p. 150, 1865, des- 

 cribed from Galifornian speciemns. 



Metridium senile Mc^IrRRicn, Trans. Royal Soc, Canada, Vol. IV, section 4, 

 p. 60, 1910, (not Actinia senilis Linn., 1767, nor Priapus si)iihs Linn., 

 1761). 



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



This species is readily distinguished l>y its smooth column, well defined 

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

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

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

 smaller than tlie 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 readih' emitted from scattered cinclida? 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 maj' have a hemispherical form or become even more depressed in form. 



Its colours on the New lilngland coast are very varialile, rarely white or 

 lilotched with white. ^lost frequently its colour is dull yello^^-ish brown, dark 

 (ilive-colour, or chestnut brown to umber brown and often lilotched or streaked 

 ^\■ith fighter colours; sometimes it is pale buff, salmon-colour or flesh-colour, 

 rr.reljr brick-red. The tentacles are usuallj- paler or even white. 



Professor W. R. Coe, who was one of thcnaturahsts on theHarriman Alaska 

 I'^xpedition, 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 ncarlj- so. 



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

 fission; by Ijudding 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. 



