120 
CLASS ORDER II. 
favours the presumption that, they are placed as in 
the preceding genera, at the extremities of the 
branches. The Corallinas, far from indicating this 
character, appear on the contrary covered on the 
surface with polypiferous filaments, which, though 
scarcely retractile, are yet endowed with a move- 
ment that can only be attributed to life. 
The Janias resemble the Corallinas in their sub- 
stance, and particularly in those oval bodies which 
are looked upon as ovaria, and thus form a perfect 
analogy between the two groups ; this analogy is 
most discernible in the Jania corniculata , which 
sometimes exhibits all the characters of a true Co- 
ralline in its lower part, whilst the upper is wholly 
devoid of them. 
Thus then, as previously observed, may these Po- 
lypidoms be considered as intermediates between the 
Corallinas and the Galaxauras, without decidedly be- 
longing to either the one or the other. 
In the bosom of the sea, the Janias are of a green- 
ish violet ; this colour changes to a rose, or bright red, 
which becomes pure white by the action of air and light. 
Their height never exceeds four centimetres, but 
some of them are not more than three millemetres high. 
They are found in all latitudes, and in all depths ; 
in general parasites on the marine plants, which they 
sometimes wholly cover with a thick coating. 
GIBBOUS. 
1. Jania gibbosa. Articulations swelled in the 
central part : height from one to three millemetres. 
On the Fucus latifolius of the Red Sea. 
