94 
CLASS L— ORDER II. 
The branches are placed on the flat part of the 
stem ; their divisions, always alternate, have in their 
length one or two articulations. 
The ovaria, nearly sessile, frequently axillary, some- 
times dispersed, resemble an antique vase ; at certain 
times their opening is closed by a lid with a concentric 
zone. 
Their substance is horny ; their colour a dull and 
deep fawn ; their height a decimetre. 
Australasia. 
FOUR-CELLED. 
1. Salacia tetracyttara. The only species known. 
— Plate 6. fig. 3. a. B. C. 
CYMODOCEAo 
Plant-like ; cells cylindrical, varying in length, 
filiform, alternate or opposite ; stem fistular, marked 
with rings below, plain above, and without interior 
division. 
These Polypidoms bear a strong resemblance to the 
Tubularias ; but the Polypi belonging to the last-men- 
tioned order are always placed at the summits of their 
branches, whilst those of the Cymodoceas are as con- 
stantly found on the branches or their divisions. The 
stem of the Cymodoceas is a continued horny or car- 
tilaginous tube, simple or branching, and which in a 
living state should be filled with an irritable animal 
