35 
Microscopical Society of Victoria. 
completely free from the pinna, forming a wide aperture. Cauline 
sarcotliecte, two on the stem at the base of each pinna, similar in 
structure to the laterals, the upper one larger; the lower usually 
with two, and the upper with three small sub-tubular orifices close 
to the upper margin, which is completely free, as in the laterals. 
Gonotliecffi 1 Colour, brown. Hob. Queenscliff. 
(See the remarks on this species in the preliminary note on the 
genus.) 
A. parvula. n. sp. Plate XIV, fig. 3. 
Hydrorhiza stout, shoots attaining a height of nearly an inch, 
pinnate; pinnre close, alternate, straight, ascending, each springing 
from the lower part of an internode, and both series borne 
towards the front 0 f the stem. Hydrotlieca: urceolate, narrowed 
towards the base, set at an angle of about 35°; a fold or constric¬ 
tion crossing the back part of the cell in a direction vertical to the 
pinna; aperture sub-plicate, with five teeth on each side, the first 
from the front everted, and an incurved slender one in front. 
Hydrothecal internodes narrowest at the proximal end, with two 
folds or constrictions partly surrounding them ; one transverse, 
opposite the fold in the hydrotheca, the other directed obliquely 
forward from the base of the lateral sarcotherae. Mesial sarcotheca 
about as long as the hydrotlieca, and projecting from it, adnate to 
the hydrotlieca to within a short distance from the aperture, and 
mainly rising from it, but continuous with the pinna by a small 
part of its base ; obliquely truncate, canaliculate, with an orifice 
communicating with the hydrotheca immediately below the external 
aperture. Lateral sarcotheca: short, canaliculate, directed forwards, 
the teeth of the hydrotheca projecting beyond them. Cauline 
sarcotheca:, two on the Stem at the base of each pinna resembling 
the laterals; one on the basal part of each pinna, small, tubular, 
not open at. the side. 
Gonangiul pinna bearing a single hydrotlieca below the corbula, 
with a joint abo\o and below it, the rest of the pinna not jointed. 
Corbuke of two kinds —(a), with six or seven pairs of broad 
leaflets completely unite 1 and forming a closed pod, as in 
A. pluma, the distal edge of each leaflet fringed with short, stout, 
tubular, canaliculate sarcotheca:; a free pinnule springing from the 
proximal rib of the corbula on one side, directed forward parallel 
D 2 
