22 THE VOYAGE OF H.M.S. CHALLENGER. 
Plumularia insignis, however, is altogether a larger and much more robust form, while 
the hydrocladia are longer and occupy a greater length of their supporting branches, ex- 
tending from the distal extremity of these nearly to the base. In Plumularia abietina, 
on the other hand, a considerable portion of the branch towards its proximal end is desti- 
tute of hydrocladia. 
The specimen had numerous individuals of an Avicula-like fry adhering to it, a 
feature which has been reproduced in the drawing. 
Dredged off Prince Edward’s Island, from a depth of 150 fathoms (7%). 
Plumularia stylifera, n. sp. (Pl. TV. figs. 1, 2). 
Trophosome.—Colony attaining a height of about an inch and a half, stem simple 
monosiphonic, hydrocladia alternate, about one-tenth of an inch in length, and with the 
hydrotheca-bearing internodes usually separated by an intervening internode which does 
not carry a hydrotheca. Hydrothecze rather large, adnate only by their base to the 
supporting internode, flanked on each side by a long slender process, which springs from 
the internode and carries a lateral nematophore on its summit; a single mesial 
nematophore borne by the hydrothecal internode at the proximal side of the hydrotheca, 
and another by the intervening internode. 
Gonosome. 
Gonangia springing from the hydrothecal internodes at the proximal side 
of the hydrotheca, ellipsoidal, with a truncated summit which opens by a lid, and with a 
pair of nematophores carried near its proximal end. 
The great leneth of the process which supports the lateral nematophore on each side 
of the hydrotheca presents a striking feature. The present species, however, is not the 
only one in which this process attains a considerable length. It is nearly as long in the 
European Plumularia catharina and in other species closely allied to the latter, as well as 
in Antennularia fascicularis of the present Report. 
Plumularia stylifera has many points of affinity with Plumularia catharina, which it 
resembles not only in the long style-like process which supports the lateral nematophore, 
but in the presence of a pair of nematophores on the proximal end of the gonangium, and 
in the general form of the hydrothecze and their supporting pinnee. Indeed, it differs 
from it mainly in its more delicate habit and shorter and more approximated hydrocladia, 
which are disposed alternately on the stem instead of being opposite, as in Plunularia 
catharina. 
Dredged off Nightingale Island, Tristan d’Acunha, Station 135, from a depth of 
100-150 fathoms, 
Plumularia armata, n. sp. (Pl. IV. figs. 3, 4). 
Trophosome.—Colony attaining a height of about two inches; stem monosiphonic 
irregularly and sparingly branched, divided into internodes, each of which carries a hydro- 
