46 AGLAOPHENTA BISPINOSA. 
with the margin cut into rather shallow teeth, and with the cavity divided 
into a distal and proximal portion by a distinct intrathecal ridge of a 
sigmoid form. Supracalycine nematophores not overtopping the hydro- 
theca; mesial nematophore adnate to the proximal fourth of the hydro- 
theca, becoming free only close to its point. 
Gonosome not known. 
Dredged off Alligator Reef, from a depth of 110 fathoms. 
The remarkable sigmoid form of the intrathecal ridge constitutes a 
very distinctive character of this species. Another striking feature is 
found in the numerous well-marked septal ridges by which the inter- 
nodes of the pinnez have their cavity divided into intercommunicating 
chambers. It is a strong, rather rigid species, and attains a considerable 
size; but as the specimen had lost its hydrorhizal extremity, the entire 
length attaimed by it could not be determined with certainty. 
In the absence of the gonosome its reference to the genus Aglao- 
phenia is of course only provisional. 
Aglaophenia bispinosa. 
Pls. XXVIL,. and XX VII 
Trophosome.— Stem attaining a height of eight inches, stout, simple, 
rising from an entangled mass of branching tubular filaments, fascicled 
below, and presenting from distance to distance knot-like projections ; 
pinne alternate, attaining a length of nearly an inch and a half. Hy- 
drothece deep, widening upwards; margin with a single, strong tooth-like 
process in front, and with short, blunt teeth in the rest of its extent ; 
intrathecal ridge not conspicuous. Supracalycine nematophores stout, 
not overtopping the hydrotheca; mesial nematophores two in number, 
the distal one adnate to the hydrotheca, along which it extends for 
about one third of the height of the hydrotheca, the proximal one forming 
a short, stout spine-like process just below the distal. 
Gonosome. — Corbulee open, formed by two alternate or sub-opposite 
series of free, rib-like processes, each of which carries near its base a 
small hydrothecal cup, and along its distal margin a series of numerous 
tooth-like nematophores; the rachis of the corbula continued towards 
the common stem as a long peduncle carrying about five unchanged 
hydrothece. 
Dredged off Alligator Reef, from a depth of 156 fathoms, and off Tennessee Reef, from a depth 
of 200 fathoms. 
