28 THE VOYAGE OF H.M.S. CHALLENGER. 
porting internode, two small nematophores of the ordinary Eleutheroplean type are 
developed. 
The close proximity of the mesial nematophore to the base of the hydrotheca, as seen 
in the present species, is also a very unusual feature in the Eleutheroplea. 
Kirehenpauer?* describes and figures a Plumularian brought by von Martens from the 
Philippine Islands. He refers it to the Plumularia effusa of Busk, a species obtained 
in Torres Strait during the exploratory voyage of the “ Rattlesnake.”’ In the form of 
the hydrothece, and of their supporting pinne, and in the form and arrangement of 
the nematophores, the species figured by Kirchenpauer agrees closely with that here 
described. No notice, however, is. taken of the series of spine-bearing internodes in 
which the branches of Acanthella terminate. Specimens of the present species from the 
collection of the Challenger have been examined by Mr. Busk, and referred by him to the 
Plumularia effusa of the voyage of the “ Rattlesnake,” and an opportunity he has given 
me of comparing the Challenger Hydroid. with authentic specimens of his Plumularia 
effusa, has convinced me of the justice of this identification. 
Acanthella effusa was dredged off Cape York, Torres Strait, and also from reefs off 
Zamboanga, at a depth of 10 fathoms. 
Schizotricha, nov.. gen. 
Name from oxi€w, to divide, and Opié, a hair, in allusion to the bifurcation of the hydrocladia. 
GENERIC CHARACTER. Trophosome.—Hydrocladia pinnately disposed, once, twice, or 
oftener bifurcating. 
Gronosome—Gonangia springing from the hydrocladia. 
The genus Schizotricha is essentially characterised by the bifurcation of its hydrotheca- 
bearing ramuli. The collection contains two species, in one of which the ramuli bifurcate 
only once, while in the other, three, four; or probably a greater number of bifurcations 
are present. 
Schizotricha unifurcata, n. sp. (PL. VIL. figs. 1-8). 
Colony attaining a height of about five inches; stem irregularly 
branched, fascicled, rooted by a dense mass of entangled filaments ; hydrocladia alternate, 
Trophosome. 
about seven-tenths of an inch in length, dividing each into two similar branches at a short 
distance from its origin. Hydrothecee with even margin, rather deep, adnate to the sup- 
porting internode by their entire height ; besides the pair of lateral nematophores, there 
is a single mesial nematophore carried by the internode near its proximal end; a hydro- 
theca without nematophores carried in the angle of the bifurcation. 
1 Kirchenpauer, loc. cit., Band vi. 
2 Voyage of “ Rattlesnake,” vol. i. p. 400. 
oe ih 
