24 THE VOYAGE OF H.M.S. CHALLENGER. 
Notwithstanding the many exceptional characters of this curious Plumularian, | 
believe it will be better to keep it in the genus Plwmularia, rather than construct 
for it a new one. 
Under the name of Plumularia obconica, Kirehenpauer describes a Plumularian from 
the Gulf of St. Vincent, Australia, which in many respects resembles the present species. 
Its female gonangium carries, asin this, on the outer surface of its walls, a longitudinal 
series of nematophores. Like Plumularia armata, also, the species is moneecious, carrying 
male and female gonangia in the same colony, while the main stem is divided into 
internodes, each carrying a hydrotheca, as in Plumulamia armata. It differs, however, 
from Plumularia armata in its shallower hydrotheca, with plicated margin, and in the 
conical roof of its female gonangium, while the stem is unbranched, and carries the hydro- 
cladia in such a way as to give them an obviously secund disposition. Kirchenpauer, 
moreover, describes the nematophores of the trophosome as monothalamic, those of the 
gonosome being of the usual bithalamic type. In Plumularia armata both sets of nemato- 
phores are bithalamic. 
The collection contains but a single specimen of Plumularia armata. It was dredged 
at Station 163, off Port Jackson ; depth, 30-35 fathoms ; bottom, red clay. 
Antennularta, Lamk. 
Antennularia, Lamarck, Hist. Nat. des An. sans Vert., Ist ed., 1815. 
Nemertesia, Lamouroux, Hist. des Pol. Coral. flex., 1816. 
Antennularia fascicularis, n. sp. (PI. IV. figs. 5, 6). 
Trophosome.—Colony attaining a height of upwards of three inches; stem thick, 
sub-dichotomously branched, formed of a multitude of coalesced tubes, which give off on 
all sides irregularly scattered hydrocladia, which carry the hydrothece on alternate 
internodes, and are about two-tenths of an inch in length. Hydrothecee rather large, 
campanuliform, adnate by their base only to the supporting internode, flanked on each 
side by a long style-like process, which supports on its summit a lateral nematophore ; 
one mesial nematophore carried by the hydrothecal internode near its proximal end, and 
three by the intervening internode. 
(ronosome.—Gonangia springing laterally from the hydrothecal internodes each at 
the proximal side of a hydrotheca, obovate, supported on a short stalk and carrying a pair 
of nematophores close to its proximal end. 
A more extended comparison of Antennularia antennina of our own shores, in which 
the hydrocladia are verticillate, with those forms in which they are more or less scattered, 
has led me to regard this difference as of less systematic importance than I had formerly 
believed, and has induced me to assign to it a specific rather than a generic value. When, 
