OF THE KERGUELEN REGION OF THE GREAT SOUTHERN OCEAN. 355 



Alcyonaria : 



* Callozostron mircibilis,^ Wright. 



Pennatulida - : 



*Umhellida carpenteri^^ KoUiker. 



* 



magnijiora, Kolliker. 



Antipatharia : 



* Bathypathes tenuis. Brook. 



ACTINIARIA ^ : 



9' 



*Bunodes minuta, Hertwis;. 

 Cereus spinosus, Hertwig. 



1 The axis in the imperfect specimen dredged of this deep-sea form [Calloxostron mirahilis] is about 280 mm. in 

 length, it is extremely flexible, and nearly 20 mm. in widest diameter. The colony strongly reminds one at first sight 

 of some gigantic Annelid. ... It seems probable that this species lived prostrate in the mud, and possibly there 

 may have been some power of expansion and contraction in the colon}'. It was dredged in the most southern station 

 reached by the Challenger. — (Wright and Studer, Zool. Chall. Exp., part C4, pp. 48, 49.) 



^ It follows from all these facts that the simpler forms of the Pennatulida, especially those with sessile polyps, 

 inhabit great depths. The presence of their less complex representatives in deep water has also been shown in other 

 invertebrate groups. These simpler forms are probably also the oldest, and may be regarded as the last remnants of an 

 extinct primary creation. The Protoptilidre and the Umljellulidaj are the principal representatives of these old forms, 

 and of these two families especially the Challenger Expedition has discovered a hxrge number of species with a wide 

 distribution. This addition to our knowledge makes it possible to gain a better insight than formerly into the 

 development of the whole group. — (Kolliker, Zool. Chall. Exp., part 3, p. 39.) 



3 The five specimens of Umhdhda carpenteri showed a very interesting gradation from a bilateral to an ai)parently 

 irregular arrangement of the polyps. One specimen had one terminal and two lateral polyps ; another specimen 

 had four polyps, all lateral ; a third specimen had one terminal polyp, two lateral on the ri^ht and one only on the 

 left side ; in a fourth there were eight polyps, of different sizes, so disposed that they formed a rosette surrounding a 

 small dorsal area of the raohis of a stellate form, but amongst these polyps the terminal one was easily recognisable, as 

 the axis ended in its base, and the other seven could be interpreted as lateral polyps arising from a shortened rachis ; 

 the fifth specimen finally showed eight polyps, arranged in the form of a rosette, and surrounding like a cup a ninth 

 middle polyp, but this was not the terminal one in which the axis ended, one of the eight had this signification. — 

 (Kolliker, Zool. Chall. Exp., part 3, pp. 23-4.) 



^ The varying character of the deep-sea fauna leads us to the question, has life in the great depths a visible 

 influence on the organisation of the Actinite 1 This influence can be distinctly recognised in many forms, and is shown 

 by the nature of the tentacles wliich have undergone retrograde formation, and are transformed first into tubes, and 

 afterwards into simple openings in the oral disk. In Paractia tuhulifera (1875 fathoms) the tentacles have the same 

 constitution as in the majority of Actinia?, except in one point, that the terminal opening, which is usually small or 

 entirely wanting, gapes widely. In Polysiphonia tuherosa (565 fathoms) the tentacles have become short, slightly mov- 

 able, wide-mouthed tubes ; in Sicyonis crassa (1600 fathoms) they are small wart-like ring.s, and in Fohjatomidium 

 patens (1825 fathoms) and Polyopis striata (2160 fathoms) the walls have almost entirely disappeared, so that the 

 terminal opening forms a fissure in the oral disk, the last remains of the tentacle being represented by a circular margin 

 surrounding the fissure, and so we come finally to the genus Liponema (1875 fathoms), in which the points at which the 

 tentacles were actually placed are merely indicated by openings in the oral disk. Of the twenty-one forms from 500 to 3000 

 fathoms here described, no less than six species have therefore undergone modifications of the tentacles in the same 

 sense, whilst it has never been observed in a single one of the forms of the coast fauna, which greatly exceed the deep- 

 sea fauna in number. . . . There is another point in the mode of life of the deep-sea Actinia: which seems to me to 

 favour the transformation of the tentacles into tubes and openings. The nutriment of the deep-sea animals probably 

 consists chiefly of material which is already disintegrated, and of a soft nature when obtained. The animals often 

 ingest sand, impregnated with nutriment, from which they extract what is digestible ; at least I have repeatedly found 

 the interior of the deep-sea Actinioe full of mud. In such a mode of nutrition the long prehensile tentacles would not 

 be of the same use as they are in the littoral Actinioe, which lie in wait for booty, whilst on the other hand it would 



