476 PROFESSOR G. J. ALLMAN ON THE HYDROIDA 
Gonosome.—Corbula closed, rather elongated, with seven or eight moderately deve- 
loped serrated ribs; no free spur-like appendage at its base. 
Aglaophenia dromaius is a lax flexile species, strongly suggesting, both in size and 
form, one of the slender loose-barbed plumes of an Emu’s feather. It comes very near 
to Aglaophenia tubulifera, Hincks, from which, however, it differs by its smaller lateral 
nematophores, and by its more elongated corbulz as well as by the slighter development 
of their serrated crests, and by the absence of the spur-like appendage at their base. 
It was dredged off the Spanish coast from a depth of 539 fathoms. 
AGLAOPHENIA ELONGATA. Plate LXVII. figs. 2, 27, 2”. 
Trophosome.—Stem attaining a height of about six inches, irregularly or subalter- 
nately branched, not fascicled, divided into equal internodes; pinne slender, alternate, 
each attached to a point a little below the distal end of an internode. Hydrothece 
deep and narrow, nearly cylindrical, margin cut into distinct and equal teeth ; intrathecal 
ridge extending but a short distance from the posterior walls of the hydrotheca near the 
fundus of its cavity ; mesial nematophore adnate for nearly its entire length, and attaining 
about one third the height of the hydrotheca ; lateral nematophores scarcely overtopping 
the hydrotheca. 
Gonosome.—Corbule closed, short and deep, with about seven moderately developed 
serrated ribs. 
This is a slender, loosely branched, rather straggling form,and is especially distinguished 
by its deep narrow hydrothece. It was dredged along with Aglaophenia dromaius on 
the coast of Spain from a depth of 539 fathoms. 
HALicornariaA, Busk (modified). 
Trophosome.—Hydrocaulus with pinnate ramification. _Hydrothece usually with an 
intrathecal ridge. Nematophores fixed; lateral nematophores one on each side of the 
orifice of the hydrotheca: mesial nematophores usually adnate for a greater or less 
extent to the front of the hydrotheca, rarely free. 
Gonosome.—Gonangia not included in corbule or protected by gonangial branches. 
The generic name Halicornaria was proposed by Busk for such Plumularide as are 
deprived of corbul, and are otherwise referable to the type of the Plumularia setacea of 
authors. The name of Halicornaria, however, is displaced by Lamouroux’s prior name 
of Aglaophenia, which, though applied by Lamouroux not only to the forms referable 
to the type of Plumularia setacea but to those also which have Plumularia pluma of 
authors as their type, may be now restricted to the latter, thus allowing the Plumu- 
laria setacea and its allies to retain undisturbed possession of the name of Plumularia 
assigned to both forms by Lamarck. Rather than introduce a new name, I have deemed 
