Microscopical Society of Victoria. 
39 
Plumulauia. Lamarck. 
Our native species of Plumularia differ considerably from the 
British. One is simple in habit, two or three possess more or less 
developed intrathecal ridges, and several belong to that section of 
the genus which is distinguished by bearing only one calycle on 
each pinna, and which is represented by P. obliqua only among 
British species. Another form which I have found at Williamstown 
appears not to be specifically distinct from P. obliqua. Its stem is 
nearly half an inch in height, and is often produced upwards into 
long thick tendrils, having a similar structure to that of the 
hydrorhiza. 
P. indivisa. n. 8]). Plate XY, fig. 1. 
Shoots flaccid, simple, rising from a dense network of filiform 
radical fibres, and obtaining a height of one-half or three-fourths 
of an inch ; proximal part naked, upper part divided by oblique 
joints into long internodes, each bearing a hydrotheca near its 
lower extremity. Hydrothecie distant, cup-slmped, set at an angle 
of about 40°, base wide and rounded, aperture entire. Sarcotheca? 
bitlialamic, one at each side of the hydrotheca, pedunculate; one 
in front, and one about midway between every two hydrotheca?, 
on the same internodc as the lower. 
Gonotheca?: female, ovate, nearly three times as long as the 
hydrotheca?; male, as broad as the female, but shorter, flabelliform; 
both kinds with two lateral sarcotheca? near the pedicle. 
Hydrorhiza and proximal part of the shoots brown, upper part 
transparent and nearly colourless. Hub ., Williamstown. 
P. puoDUCTA. n. sp. Plate XY, fig. 3. 
Hydrorhiza stout, shoots about one-third of an inch in height, 
pinnate; puinse alternate, one borne about the middle of each 
internode. Hydrotheca? set at an angle of about 30°, cup-shaped, 
but with the back part much produced upwards ; front wall of 
the cell doubled inwards just below the aperture, and continued 
into a transverse septum or intrathecal ridge, which extends 
more than half across the cavity of the cell; aperture entire, 
expanded in front. Sarcotheca? bitlialamic, one in front of each 
hydrotheca only. 
