26 SYDNEY J. HICKSON anp F. H. GRAVELY. 
length, and from 1°5-2°0 mm. in diameter at the mouth. The margin is armed with 
15-20 blunt denticulations. The hydranths are large, but of the usual form in the 
genus, and provided with about 30 tentacles 1°5 mm. in length. 
Gonosome.—The mature gonotheca is 2°5 x 1°2 mm. in size, tall and cylindrical. 
The proximal part of the gonotheca is slightly swollen, and the distal end almost 
straight. It is supported by a short annulated pedicel arising directly from the 
hydrorhiza. 
The specimens attributed to Hartlaub’s species differ from the type in one or two 
particulars. The hydrothece are not so fully expanded distally, the reduplications (?) 
of the stem are not so well-marked, and the gonothece are very different in shape 
from those of the specimens from Calbuco.* But without further evidence as to the 
sex and structure of the gonophores of this type we do not feel justified in creating a 
special specific name for them. 
SUB-FAMILY HALECIINAE. 
The genera that are usually included in the sub-family /Halectinae (Haleciidae, 
Hincks) are characterised by the rudimentary condition of the hydrothece. The 
tubular structures arising from the hydrocladia surround, like a collar, the base of the 
hydranths, but are quite insufticient to enclose and thereby afford protection to them 
when retracted. , 
It is, in our opinion, unfortunate that the term ‘“ hydrophore” has come into 
general use for this rudimentary form of hydrotheca. There are many examples to be 
found in the Calyptoblastea of hydrothecee that are not cup-shaped, such as the 
cylindrical hydrothecee of Sertularella formosa and Synthecium cylindricum , (see 
Nutting, 19: p. 14), and it would be practically impossible to limit the use of the term 
to hydrothecz, that are tubular or cylindrical in shape. The use of the term hydro- - 
phore for those hydrothecee only which are not capable of receiving the retracted 
hydranth would also be inconvenient. It is, therefore, the best course to adopt to 
abandon the use of the term hydrophore altogether. 
The genus //alecium is usually regarded as distinguished from its allies Dip- 
locyathus (Allman), Hydrodendron (Sars), and Ophiodes (Hincks) by the absence of 
nematophores ; but one of us has observed the presence of nematophores on the 
specimens of J/alecium arboreum obtained by the ‘ Challenger’ (8: p. 10, Pl. IV., 
figs. 1-3) and now in the British Museum, which were overlooked by Allman, and the 
specimens which we attribute to the same species have also nematophores. It does not 
seem to us convenient to again split up the genus //aleciwm into groups containing 
those which do and those which do not possess nematophores, but rather to add to the 
characters of the genus, that ‘‘ nematophores may or may not be present.” As regards 
the use of the term “ nematophore,” it is necessary to explain that we have adopted the 
* On the coast of Chili, approximately 41° S. by 71° W. 
