FORSTER COOPER—ANTIPATHARTA. 303 
Parantipathes. As in the case of the spines the great difficulty occurs among the closely 
allied forms. In the genus Antipathes, for example, there are a great number of forms 
differing from one another in general appearance, but with polyps of closely similar size 
and shape. The polyps of the large bushy 4. adies are hardly distinguishable from those 
of the small delicate 4. gracilis, although the two forms are in size and general appearance 
and method of growth entirely different. It becomes all the more difficult therefore to 
use the polyp form to distinguish between the more closely resembling colonies. The 
main features of anatomy are very constant over the whole group, the difference 
even between Schizopathes and the rest is more apparent than real. It may be that 
careful comparison will show some constant characters of specific nature in the position 
of the nematocysts or the thickness of the mesoglea, though this does not seem 
very probable. 
It appears, then, that beyond the broad distinctions alluded to above, there is really 
nothing upon which to depend as a sure guide to a species in this group. In spite of 
this we have to make use of such characters as occur in order to name forms in the hope 
that further collections and study will in process of time throw more light on the 
question. 
Genus STICHOPATHES, Brook. 
This genus includes those forms which have the polyps arranged on one side of the 
stem only, and in the case of those with spiral stems invariably on the outer side. There 
are three types of growth—(1) straight and (2) spirally coiled, both are usually long and 
slightly tapering; (8) a third type is sometimes met with in which the growth is 
sinuous and is thus intermediate between the two. 
The polyps are either flat with long digitiform tentacles, or stouter with short ones: 
the state of preservation, however, has so much to do with the polyp-form that too much 
stress must not be laid on shape alone. The anatomy as far as observed does not depart 
from that of the normal antipatharian polyp. 
In many species the spines are of unequal size on two opposite sides of the stem. 
When this occurs, there is invariably a gradation in size from the smaller on one side to 
the larger on the other (fig. 2a, p. 305), and in no case was a sudden alteration observed. 
This difference has previously been observed in a few species, but in the present 
collection is of very general occurrence. It is possible that this point has been missed in 
some cases, as the skeletal axis generally seems to lie, when under examination, in such 
a position that the sides on which the spines are of equal size, @. e. at right angles to the 
axis on which they are unequal, are alone to be seen. In order to see the inequality of 
the spines, the piece of the axis must be carefully rotated, which in the case of a small 
curved piece is not always easy. A convenient method is to cut off a small piece and fix 
it in a small square of cork, when by looking down on the cut section the irregularity of 
the spines as well as the number of their rows can easily be observed. 
Small secondary spines occur in some forms, but are not of general occurrence; their 
arrangement is always without any definite order. As is the case in other orders of 
Antipatharia, the spines may and frequently do vary considerably in size, shape and 
