AGLAOPHENIA APOCARPA. 41 
which the leaflets of the corbula give off at their base form a series of 
pinne upon each side of the rachis, very obvious when the corbula is viewed 
either from above or below. These pinne-like processes carry nemato- 
phores along their upper side, and when viewed from below are seen to 
send off a somewhat triangular, flat, wing-like expansion from the lower. 
The beak-like extension of the rachis carries also on its upper surface 
nematophores which are disposed in two pairs. The peduncle of the cor- 
bula carries a single hydrotheca. 
Aglaophenia lophocarpa. 
Pl. XXIV. Figs. 1-4. 
Trophosome. — Hydrocaulus attaining a height of between two and three 
inches, simple, not fascicled; pinne alternate, springing from a point near 
the distal end of each internode. Hydrothece deep, somewhat tumid below, 
margin slightly everted, with nine equal very distinct teeth; intrathecal 
ridge transverse. Supracalycine nematophores slightly overtopping the 
hydrothecx ; mesial nematophore adnate to within a very short distance 
of its summit, and attaining nearly half the height of the hydrothece ; 
cauline nematophores two on each internode of main stem, one close to the 
axil of the pinna and the other near the proximal end of the internode. 
Gronosome. — Corbula with about ten pairs of leaflets; leaflets broad, 
united into a completely closed corbula, the distal margin of each carry- 
ing numerous well-developed denticles, and projecting from the sides of 
the corbula in the form of a pectinated ridge which is continued as a 
free serrated crest beyond the roof; a spur-like denticle at the base of 
each leaflet; peduncle of corbula carrying a single hydrotheca. 
Off Tortugas, from a depth of 68 fathoms. 
The corbula of this species, with its pectinated ridges and crests, is a very 
beautiful object, and affords a well-marked specific character. 
Aglaophenia apocarpa. 
Pl. XXIV. Figs. 5-9. 
Trophosome. — Hydrocaulus attainmg a height of about two inches, 
simple, not fascicled; pinne alternate; internodes of pinnze somewhat 
bent backwards at their proximal end so as to give rise to a slight 
angular bend at the point of junction of every two internodes. Hydro- 
thecee deep; margin with about nine deeply cut teeth, slightly everted ; 
6 
