walls of the stem-canals. They recognised four genera: i. Paranephthya; 2. Scleronephthya; 
3. Chironephthya; and 4. Siphonogorgia. 
1. As regards the genus Paranephthya, it stands markedly by itself, in having non- 
retractile polyps, tentacles folded over the mouth when at rest, peculiar foliaceous and spiny 
clubs, and a distinctive dusty or scaly appearance when the surface is dry. Its position among 
the Siphonogorginae seems to require fresh inquiry. Thus Paranephthya capittUifera W. and S., 
should be referred, as Kukenthal noticed, to the genus Capnella among the Nephthyidae. 
2. As regards the genus Scleronephthya, established by Wright and Studer, it is much 
nearer the Siphonogorgia type, having large spiny spindles and distinct “crown and points”. The 
canals, however, are absent from the centre of the stem, which forms an irregular axis. The 
shape and armature of the polyps come near to what is seen in Nephthya, and the bushy 
appearance of the ends of the branches is like Dendronephthya (or Spongodes) rather than 
Siphonogorgia. There is no trace of supporting bundles, and the tough compact consistence of 
stem and branches, whose walls do not collapse either in spirit or in the dry condition, distinguishes 
the genus from the true Spongodinse. 
3. and 4. Wright and Studer separated off the new genus Chironephthya from Siphono¬ 
gorgia, mainly on the ground that “the polyps occur along the entire course of the branches 
and are less retractile”. 
The criticisms of Kukenthal and of Hickson seem to render this separation quite untenable. 
Hickson sums up the contrasts as follows: 
“I would suggest that the name Chironephthya be retained for the species or facies 
with a form and mode of branching resembling that of the genus Nephthya, with anthocodise 
rarely completely retracted in preserved specimens, and with four principal spicules arranged in 
chevron, in the points of the anthocodiae; and that the name Siphonogorgia be retained for 
species or facies of more massive Gorgonia-like form of growth, with anthocodiae capable of 
complete retraction within the general coenenchyma, and with spicules irregularly placed, or 
arranged in a fan-like manner in the points of the anthocodiae”. 
But he proceeds to point out that a given specimen may be in some of its characters 
Siphonogorgia-like and in others Chironephthya-like. 
Many species that have been referred to the genus Siphonogorgia have anthocodiae 
completely retracted, and in most cases the spicules of the points are arranged in chevron, as 
in S. annectens , S', cylhidrata , etc., though sometimes with two pairs of principal spicules, 
as in S. kdllikeri. 
The difference in the thickness of the canal walls cannot be considered as diagnostic, as 
some species have walls of medium thickness and might be placed midway between the two 
types. In S. godefroyi there is a very thick, rigid, outer wall, and the canals in the centre 
are separated by thin partitions. 
It is therefore probable that all species of Siphonogorgia and Chironephthya should be 
included under the older name Siphonogorgia with the following characteristics : 
(1) colony rigid, upright, ramified; 
(2) coenenchymal tissue consisting of irregularly arranged spicules, with connective tissue between, 
and no distinct cortex; 
