of Edinburgh, Session 1883“84. 
719 
is some 10-15° F. higher than in the other. We have thus two 
areas in which all factors influencing the distribution of animals 
are approximately eliminated, save and excepting that of tempera- 
ture, so that here, if anywhere, we may hope for an opportunity of 
determining the influence due to this important factor. 
With the view of investigating this matter, so far as the Ophiu- 
roids are concerned, the table on the next page has been drawn up, 
which includes all the results obtained by Porcupine,” 
“Knight Errant,” and “Triton” which are applicable to the 
problem under discussion. In order to render the results strictly 
comparable, only those stations are considered v^hich are clearly 
within one area or the other, none, of course, being admitted which 
are at a less depth than the top of the Wyville-Thomson Ridge, 
that is, about 300 fathoms. The depth and bottom temperature of 
each station are given, and the number of specimens obtained at 
each is shown by the figures in the several columns. 
It will be obvious that in attempting to draw conclusions from 
such a table, the utmost caution must be observed ; the numbers are 
so small, that any extensive series of dredgings will be sure to alter 
them very considerably. For instance, the whole of the expeditions 
together, prior to the “ Triton,” only obtained one specimen of 
Ophioglyylia mirantiaca, while only three dredgings on that cruise 
yielded together forty-five specimens. 
Still as no further data are at present available, the best use 
possible must be made of these, it being understood that the results 
are only provisional. It appears then, that while eight species were 
found both in the warm and cold areas, six were peculiar to the 
latter and six to the formen 
These facts suggest that there are certain forms which flourish in 
warmer, whilst others are better adapted to colder waters ; but in 
order to confirm this view, it will be well to state what is known of 
the distribution, with respect to temperature, of each of the species 
in question in other localities ; unfortunately our knowledge upon 
this point is very fragmentary, because it is only of recent years 
that dredgings have been made, while, at the same time, accurate 
physical observations have been taken, but such facts as I have 
been able to collect are given in the following paragraphs. 
Amphiiira hellis, Lym,, has previously been found only at three 
