356 DR MURRAY ON THE DEEP AND SHALLOW- WATER MARINE FAUNA 



*Corallimorphus obtectus, Hertwig. 

 „ rigidtis, Moseley. 



Liponemo, multi'poru'm^ Hertwig. 

 ^Porponia elongata^ Hertwig. 

 ^Sicyonis crassa,^ Hertwig. ' 

 *Tealidium cingulatum* Hertwig. 



Another Actinian undetermined. 



Corals : 



Bathyactis symmetrica '' (Pourtales). 



be a decided advantage to the animals to be furnished with numerous inhalent tubes and openings through which they 

 can absorb semi-liquid nourishment. This then is the advantage of the stomidia and tubular tentacles. The retrograde 

 formation of the tentacles is by no means the only point to be taken into consideration in the varying character of the 

 deep-sea Actiniae, the position of the septa being equally important. The arrangement of the septa typical of the 

 Hexactiniae is only present in thirteen genera, among which I reckon Ophiodiscus and Polystomidium, in which we 

 meet with the differentiation of muscular and genital septa which is otherwise unknown, and the genera Stephanactis 

 and Amphianthits, in which we find some approach to the Antipatharia. The other four genera differ from one 

 another as well as from the Hexactinite in the arrangement of the septa. They swell the mimber of the varying forms 

 represented in shallow water by the Zoanthese, Cerianthe^e, and Edwardsiie, and therefore seem to indicate that the 

 diversity in the structure of the Anthozoa was formerly much greater than it is at present, and that the remains of this 

 diversity have been more extensively preserved in the depths of the sea than in the shallow waters. In this way we 

 can recognise peculiarities in deep-sea Actinia; which are common to the whole deep-sea fauna. — (Hertwig, Zool. Chall. 

 Exp^ part 15, pp. 1.32-134.) 



' The tentacles in Liponema raultiporum have undergone retrograde formation to a greater extent than in any 

 other Actinia, as there are not the smallest remains of their walls, while in Polyopis these can still be recognised as 

 thickened ridges surrounding the openings.— (HERrmG, Zool. Chall. Exj>., part 15, p. 129.) 



- Whilst the majority of Acttnise, especially those from great depths, form a short column, and are frequently 

 flattened into a disk, the body form of Porponia elonyata, from 2600 fathoms, approximates that of the elongated 

 Cerianthidae. In both specimens examined the body, though contracted, was twice as long as high. It is broadest in 

 the region of the oral disk, below which it becomes a little narrower, and then becomes broader again at the pedal 

 disk, by which it is firmly attached to the bottom.— (Hertwig, Zool. Chall. Exp., part 15, p. 125.) 



3 Sicyonis crassa is one of the most interesting Actiniae dredged from great depths, both on account of the consti- 

 tution of the tentacles and of the arrangement of the septa.— (Hertwig, Zool. Chall. Exp., part 15, p. 98.) 



* The single specimen of Tealidium ciwjulatum, which was taken attached to a stone from a depth of 1800 fathoms, 

 belongs to the smallest forms among the Challenger material. It is so strongly contracted that the wall closes over the 

 entrance to the oral disk till only a small opening is left. — (Hertwig, Zool. Chall. Exp., part 15, p. 51.) 



* Bathyactis syrarnetrica was dredged by the Challenger in all parts of the world. It varies very much in size 

 and appearance, the smallest specimens obtained measuring 3 mm. and the large=t 40 mm. in diameter ; the increase in 

 size being e\-idently not a matter of age and growth as of different development under different conditions. . . . The 

 inspection of a long series of specimens leaves no doubt as to the identity of the large specimens with the small ones. 

 The very large specimens are excessively thin and fragile, and only a small percentage of them were obtained in an 

 imbroken condition. . . . The larger specimens vary in very much the same manner as the smaller ; some have the 

 margins of their septa fused for long distances at their points of junction ; others show little fusion of the septal 

 mai^ins. In some specimens the fusion of the septal margins is very irregular, in one a spongy outgrowth is developed 

 from the coverings of one of the deltas. In some of the largest specimens there is scarcely any trace of a columella ; 

 in others there is a large oval one, composed of a membranous expansion, through which the spines project. . . . After 

 tabulating all the occasions on which this coral was dredged, I cannot succeed in establishing any relation between 

 the size of the specimens dredged, and the conditions of depth, bottom, or temperature. No large specimen was dredged 

 in less than from 200 to 360 fathoms, but from one of these depths a broken specimen, which must have measured 

 more than 30 mm. in diameter, was obtained. Small, apparently adult, specimens of the stouter variet}', measuring 

 only 9 mm. in diameter, were dredged from such depths as 2440 fathoms on several occasions. The greater number 

 of very large specimens were obtained from deep water, many being brought up at one haul of the dredge, as at Station 

 147, in the South Indian Ocean, where twenty or thirty specimens were obtained from 1600 fathoms, curiously enough, 

 all of them large, no young ones being found amongst them. Bathyactis symmetrica -was found to have a wider range 



