52 
THE VOYAGE OF H.M.S. CHALLENGER. 
The gonangia are very beautiful. The regularity and prominence of the annular 
ridges constitute a feature in the highest degree attractive. The distal end is prolonged 
into a short, wide neck, which terminates in a saucer-shaped summit, from the centre of 
which rises a narrow, cylindrical tube, which carries the relatively small orifice of the 
gonangium. 
The annular ridges, which are very prominent on the apocauline or outer side of the 
gonangium, are nearly obsolete on the inner or epicauline side, a condition which is 
obviously connected with the close proximity of this side to the opposed surface of the 
stem. 
Sertularia gracilis has considerable resemblance to Sertularia tricuspidata, Alder. 
It differs from it in the absence of annulation at the distal side of every hydrotheca, 
in the hydrothecse having only two marginal cusps, and in the more elongated 
gonangia. 
Sertularia annulata, n. sp. (PI. XXIV. figs. 2, 2a). 
Trophosome . — Stem fascicled towards the base, becoming monosiphonic distally, 
irregularly or subpinnately branched, set with pinnately disposed, alternate ramuli, stem 
and ramuli divided into short internodes, every internode carrying a hydrotheca. 
Hydrothecse alternate, nearly cylindrical, adnate to the internode for somewhat more than 
half their height, then becoming free and divergent, distinctly annulated for some dis- 
tance from the orifice, margin of orifice with four short, broad cusps. 
Gonosome not present. 
Locality . — Station 163b, off Port Jackson, Australia; depth, 35 fathoms. 
Sertularia annulata is a strong-growing form. The main stem and its principal 
branches are stout, and fascicled towards the proximal ends, but become monosiphonic 
distally, and are regularly set with rather long, alternate, equidistant, monosiphonic 
pinnse. The annulation of the hydrothecse is well marked, and extends from the orifice 
about halfway towards the base. 
Sertularia leiocarpa, n. sp. (PI. XXV. figs. 1, la). 
Trophosome . — Hydrocaulus monosiphonic, irregularly branched, geniculated, every 
internode increasing in thickness from its proximal to its distal end. Hydrothecse 
alternate, springing from the salient angles of the geniculations, distant, deep, tubular, 
narrowing towards the summit, adnate to the internode for about one-third of their 
height, then diverging at a wide angle, and terminating in a subquadrate orifice with four 
minute cusps. 
