April 14, 1870] 
NATURE 
613 
forms with one exquisitely figured by Seguenza, and which he 
calls Amphihelia miocenica, Seg., the generic affinities of all 
become startlingly evident. The very ‘numerous specimens of 
small branching Ocudinide, which were dredged up in the Porci- 
pine Expedition (No. 54) and tothe north-west of the spot in the 
cold area, at a depth from 363 to 600 fathoms, present singular 
variations of structure in the buds and calices upon the same 
stems. A careful examination of them, assisted by a comparison 
between them and the well-known recent and fossil Amphihelie, 
the fossil and recent Dzfloheliz, and the smaller specimens of 
Lophohelic, leads to the belief that Amphihelia is identical generi- 
cally with Diplohelia, and very closely allied with Zoshohelia. 
Indeed, the distinction between the Zophohelie and Amphihelie 
is of the slightest kind. The species of the genus Amphihelia 
dredged up in the Porcupine Expedition are numerous :—— 
1, Amphihelia (Diplohelia) profunda, Portales, sp. 
2. oculata, Levzvews, sp. 
3 miocenica, Segzersa. 
4. —— Atlantica, xodis. 
5. —— ornata, zobzs. 
The distinction between these massive and densely hard corals 
(whose calices are principally on one side of the ccenenchyma of 
the stem) and the Sty/asters is very evident. M. de Pourtales 
has described a pretty red-coloured A//opora miniata dredged in 
100 to 324 fathoms off the Florida Reef ; but it is very distinct 
from the species discovered in the late deep-sea dredging ex- 
peditions. A//opora has no fossil representatives. 
Balanophyllia (Thecopsammia) socialis, Pourtales.—Six speci- 
mens of a simple perforate coral were dredged up in lat. 
59° 56’ N., long. 6° 27’ W., 363 fathoms, temperature 31°°8 
(No. 54), and one in lat. 61° 10’ N., long. 2° 21’ W., 
345 fathoms, temperature 29°°9 (No. 65). The six speci- 
mens are of different sizes and ages; and although they 
present considerable variation in shape and_ septal de- 
velopment, they evidently belong to one type. The solitary 
coral form (No. 65) is larger than the others, but it belongs to 
the same species. Notwithstanding the temperature in which 
the corals were found, and the depth of the sea, they are strong 
and well-developed forms, evidencing an active and abundant 
nutrition. There is no difficulty in classifying the speci- 
mens with the Zhecopsammie of Pourtales.  TZhecopsammia 
socialis, Pourtales, was dredged up in from 100 to 300 fathoms, 
off Sombrero, near Florida, in the course of the Gulf Stream. 
The varieties and the original type are very isolated forms in the 
great genus Balanophyllia. They have only a very remote affinity 
with the West Indian recent Ba/anophylliz, with those of the 
Crag, the Faluns, and the Eastern tertiaries. The British 
forms appear to have emigrated from the south-west, and pro- 
bably the original type wandered, through the agency of the 
Gulf Stream, which carried ova and deposited them in our 
northern sea, where they have propagated, varied, and thriven. 
Pliobothrus symmetricus, Pourtales.—A specimen of this doubt- 
ful coral, which had been described by M. de Pourtales, from 
the results of dredging in from 100 to 200 fathoms, was sent to 
me by Dr. Carpenter. It came from the cold area, in from 500 
to 600 fathoms. There is no doubt that this very polyzoic- 
looking mass belongs to the American type. The tabule are 
hardly worthy to be called such, and I place the form amongst 
the Zoantharia provisionally. 
111. The species of Madrepforaria belong to genera which 
do not and have not contributed to coral-reef faunas. None 
of them are reef-builders; but all are essentially formed 
to live where rapid growth and delicately cellular structures 
are not required. The forms are strong, solid, and large; and 
their rapid and repeated gemmation proves that their nutritive 
processes were active and continuous. All the species are very 
much disposed to produce variations ; and this is especially true 
as regards those which have outlived the long age of the crag, 
the glacial period, and the subsequent time of elevations and 
subsidences, The least variable species are those which are not 
known on other areas. Two of the three species which are 
common to the West Indian deep-sea fauna and that of our 
north-western coasts are also variable. The persistence of 
Madreporaria, from the earlier Cainozoic period to the present 
time, has been an established fact for several years. Some of 
the forms which are common to the deep sea of the British area 
and to the so-called miocene of Sicily, are still existing in the 
Mediterranean. None of the species of corals found in the 
British crag are represented in the deep-sea fauna, The existence 
of Mediterranean forms in the north-west British area is in 
keeping with the discoveries of Forbes. It has, however, a 
double significance, and bears upon the presence of West Indian 
forms on the north-west British marine area, There was a com- 
munity of species between the Mediterranean and the West 
Indies in the Cainozoic period, and especially of Echinodermata, 
Mollusca, Madreporaria, and Foraminifera. After the great 
alterations of the mutual relations of land and sea which took 
place before the cold affected the fauna of the Franco-Italian 
seas, this community of species diminished ; but it lasted 
through all the period of northern glacialisation, and is proved 
still to exist slightly by comparing the Algze, the corals, 
the Echinodermata, and the Mollusca. The presence of 
two very characteristic Floridan species, and one less so, 
off the north of Scotland, is particularly interesting, because they 
all live in the cold area and flourish there ; whilst they appear to 
be less vigorous in the warmer Gulf Stream near Florida. It is 
impossible to fail to recognise the operation of this stream in 
producing the emigration of these three species, which are essen- 
tially American. It must be remembered, however, that the 
Cainozoic Balanophyllie were very numerous in the European 
area, but not in the American. The solidity and the power of 
gemmation of the corals within the cold area appear to be greater 
than elsewhere. Depth does not appear to have much effect 
upon the nutrition of the A/adveporaria; for those dredged up at 
600 fathoms are quite as hard and solid as those dredged up at 
300 fathoms. All the calices were stuffed with small Foramini- 
fera, and there was evidently a great abundance of food. 
There were numerous polyzoa, sponges, Foraminifera, Diato- 
mace, and delicate bivalves associated with or fixed upon the 
corals at all depths. Moreover, at from 300 to 400 fathoms a 
perforating mollusc had worked its way up the stems of some of 
the hardest specimens of Amphthelia and Lophohelia. One had 
left its excavation, which had been taken possession of bya small 
Brittle Star, and at a depth of 705 fathoms there was a pretty 
Isis. Sevfude, moreover, abound upon the corals. This is a 
fauna which, if covered up and presented to the paleontologist, 
would be, and would have been for some years past, considered 
a deep-sea one. It is a fauna which indicates the existence of 
the same processes of nutrition and of destructive assimilation 
and reproduction which are recognised in association with corre- 
sponding forms at less depths and in higher temperatures. The 
great lesson which it reads is, that vital processes can go on in 
certain animals at prodigious depths and in considerable cold, 
quite as well as in less depths and in considerable heat. It sug- 
gests that a great number of the Invertebrata are not much 
affected by temperature, and that the supply of food is the most 
important matter in their economy. 
The researches of the naturalist who obtained Polyzoa and 
Foraminifera in soundings at a depth of nearly 400 fathoms off 
the icy barrier of the South Pacific, of Wallich in the Atlantic, 
and of Alphonse Milne-Edwards in the Mediterranean, have had 
much influence upon geological thought in this age, which, so far 
as geologists are concerned, is remarkably averse to theory. For 
many years before any very deep soundings had been taken with 
a view of searching the sea-bottom for life, geologists had more 
or less definite opinions concerning the deposition of organisms 
in sediments at great depths. Certainly, more than thirty years 
ago, deep-sea deposits were separated by geologists from those 
which they considered to have been formed in shallower seas. 
The finely-divided sediment of strata containing Crinoids, 
Brachiopods, Foraminifera, and simple Madreporaria, was sup- 
posed to have been deposited in deeper water than formations 
containing large pebbles, stones, and the mollusca, whose repre- 
sentatives now live in shallows. The relations of such strata to 
each other, the first being found to overlap the last, proved that 
there was a deeper sea-fauna in the offing of the old shores 
tenanted by littoral and shallow-water species. The deposition 
of strata containing Foraminifera, Madreporaria, and Echino- 
dermata, whose limestone is remarkably free from any foreign 
substances, has been considered to have taken place in very deep 
water ; this theory has been founded upon the observations of 
the naturalist and mineralogist. Indeed, no geologist has hesi- 
tated in assigning a great depth to the origin of some deposits in 
the Laurentian, Silurian, or in any other formation. The 
“flysch,” a great sediment of the Eocene formation, has been 
considered to have been formed at a great depth and under great 
pressure. Its singular unfossiliferous character was supposed 
to be due to the absence of life at the depths of the ocean 
where the sediment collected. But this was a theory of the 
