28 



THE VOYAGE OF H.M.S. CHALLENGER. 



porting internode, two small nematopliores of tlie ordinary Eleutlieroplean 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. 



Kirchenpauer ^ 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 hydrothecse, and of their supporting pinnae, 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 Plumulana 

 effusa, has convinced me of the justice of this identification. 



Acanthella effusa was dredged ofi" Cape York, Torres Strait, and also from reefs ofi" 

 Zamboanga, at a depth of 1 fathoms. 



Schizotricha, nov. gen. 



Name from o-xi'Cw, to divide, and Bpi^, a hair, in allusion to the hifurcation of the hydrocladia. 



Generic Chaeacteb. Tropliosome. — Hydrocladia pinnately disposed, once, twice, or 

 oftener bifurcating. 



Gonosome — 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 i-amuli bifurcate 

 only once, while in the other, three, four, or probably a greater number of bifurcations 

 are present. 



Schizotricha iinifurcata, n. sp. (PI. VII. figs. 1-3). 



Trophosome. — -Colony attaining a height of about five inches ; stem irregularly 

 branched, fascicled, rooted by a dense mass of entangled filaments ; hydrocladia alternate, 

 about seven-tenths of an inch in length, dividing each into two similar branches at a short 

 distance from its origin. Hydrothecse with even margin, rather deep, aduate 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. 



' Kirchenpauer, he. cit., Band vi. 



- Voyage of " Rattlesnake," vol. i. p. 400. 



