478 PROFESSOR G. J. ALLMAN ON THE HYDROIDA 
thecal ridge. _Nematophores fixed ; lateral nematophores, one on each side of the orifice 
of the hydrotheca; mesial nematophores usually adnate for a greater or less extent to 
the front of the hydrotheca, occasionally free. 
Gonosome.—Gonangia not included in corbul, but borne on the sides or at the base 
of special protective branches, which are appendages of the pinne. 
I have constructed the genus Cladocarpus for a group of Plumularide in which the 
proper hydrothece-bearing pinne carry peculiar branching appendages (Plate LX VIII. 
fig. 1*, a, a), which are destined to support the gonangia or in some other way to afford 
protection to them. 
These appendages differ essentially from the open and closed corbule of other forms 
in the fact that they are not, like corbule, metamorphosed pinne, which take the place 
of unaltered pinne, but appendages superadded to the pinne. 
In Kirchenpauer’s subgenus Macrorhynchia, the gonangia are also borne on special 
branches (gonocladia and nematocladia, of Kirchenpauer); but these are always, as in 
the true corbulz, metamorphosed pinne. 
Macrorhynchia is further distinguished from Cladocarpus by the form of its mesial 
nematophores. which are very long, usually far surpassing the height of the hydrotheca, 
and which, as Kirchenpauer first pointed out, are always provided with a lateral as well 
as a terminal orifice after they cease to be adnate to the hydrotheca. 
It will be seen that the genus Cladocarpus is nearly allied to Aglaophenia. With 
this genus it is coincident so far as regards its trophosome; but it differs from it in its 
gonosome, which is not provided with corbulz, and instead of these receptacles has special 
ramuli, which are appendages of the pinne and are destined for the protection of the 
gonangia. Its connexion with Aglaophenia is maintained through the forms included by ~ 
Kirchenpauer in his subgenus Macrorhynchia. 
CLaDocaRPUS ForMosUS. Plate LX VIII. figs. 1, 1%, 1’. 
Trophosome.—Stem attaining a height of between two and three inches, slightly re- 
curved, simple, or with some small branches given off from its anterior aspect, fascicled 
below, pinne alternate, jointed, each joint supporting a hydrotheca, pinne near the centre 
of the series about three quarters of an inch in length, and thence decreasing in length — 
upwards and downwards. Hydrothece nearly cylindrical, with the margin provided 
with short teeth; mesial nematophore forming a stout spine extending to about half 
the height of the hydrotheca, to which it is adnate for the greater part of its length, 
becoming free at a short distance from its summit; lateral nematophores forming short 
blunt conical processes, slightly rising above the margin of the hydrotheca. Main stem 
(rachis) giving off minute nematophores, which are disposed in more or less regular 
verticils. 
Gonosome.—Gonangia-bearing ramuli springing each from the basal joint of a pinna, 
