BY W. M. BALE. 753 



This species is found growing in tufts, the largest of which 

 among my specimens is about 1^ inch high. Branches are 

 given off, sometimes profusely, from the main stem, but no 

 secondary branchlets were to be found, though possibly such 

 might be produced on older specimens. Each internode of the 

 hydrocaulus springs from a point immediately below the origin of 

 a hydrotheca-peduncle, forming a rather sharp curve upwards ; 

 and the upper part of the internode is very slightly curved 

 outwards in the opposite direction, so that the stem or branch 

 acquires a slightly zig-zag form. Thus instead of the peduncle 

 of the hydrotheca being given off at an angle with the stem- 

 internode which bears it, the peduncle is continuous with its 

 internode in a direct line, and the next internode springs off at an 

 angle. The hydrotheca when immature is entire, the summit 

 being crowned with a watch-glass-shaped cap, which ultimately 

 falls off, leaving the margin of the hydrotheca rather irregular or 

 ragged-looking. The rings of the hydrocaulus are very distinct 

 and regular, sometimes spiral, at other times simply annular. 

 "When the peduncles of the calycles are longer than would be 

 equal to the width of nine or 10 rings, the central part is smooth. 

 The gonangia are remarkable for the length they usually attain, 

 compared with their small diameter, being often less in width 

 than an average calycle, and more than three times its length. 



Obelia australis, von Lendenfeld. 



(Plate XII., hgs. 1-2). 



Primary shoots monosiphonic, about 1-1 1- inches in height, 

 sometimes with a few small branches, stem and branches flexuous, 

 with a few rings or spiral turns (mostly 3-5) just above the origin 

 of each peduncle ; 8 or 10 rings usually at the base of each st(-in 

 and branch ; peduncles ringed, those on the upper portions of the 

 hydrophyton consisting of about 4-10 rings, those on the lower 

 portions longer, often with 10-20 rings, or with the central part 

 smooth. Hydrothecae alternate, somewhat obconical, or with the 

 upper portion almost cylindrical ; not noticeably constricted at tho 



