24 THE VOYAGE OF H.M.S. CHALLENGER. 



Notwithstanding the many exceptional characters of this curious Plumuhirian, I 

 believe it will be better to keep it in the genus Plumularia, rather than construct 

 for it a new one. 



Under the name of Plumularia obconica, Kirchenpauer describes a Plumularian from 

 the Gulf of St. Vincent, Australia, which in many respects resembles the present species. 

 Its female gonangium carries, as in this, on the outer surface of its walls, a longitudinal 

 series of nematophores. Like Plumularia armata, also, the species is monoecious, carrying 

 male and female gonangia in the same colony, while the main stem is divided into 

 internodes, each carrying a hydrotheca, as in Plumularia 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 thehydro- 

 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 tj^e. In Plumularia armata both sets of nemato- 

 phores are bithalamic. 



The collection contains but a single specimen of Plumtdaria armata. It was dredged 

 at Station 163a, off Port Jackson ; depth, 30-35 fathoms ; bottom, red clay. 



Antennularia, Lamk. 



Antennularia, Lamarck, Hist. Xat. des An. sans Vert., Lst ed., 1815. 

 Nemmiesia, Lamouroux, Hist, des Pol. Coral, flex., 1816. 



Antennularia fascieularis, n. sp. (PL TV. figs. 5, 6). 



TrojyJiosome. — 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 

 aU sides irregularly scattered hydrocladia, which carry the hydrotheca on alternate 

 internodes, and are about two-tenths of an inch in length. Hydrothecse rather large, 

 campanuliform, adnate by their base only to the supporting internode. Hanked 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 intei'node. 



Gonosome. — Gonangia springing laterally from the hydrothecal internodes each at 

 the proximal side of a hydi-otheca, obovate, supported on a short stalk andcarrpng 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, 



