144 HISTORY OF BRITISH ZOOPHYTES. 
Mr. Hassall in considering his A. ramosa as a good species ; 
though there is another (slightly) branched state of A. an- 
tennina, unquestionably a mere variation, being provided 
with the tubular cells above alluded to. 
Genus VIII, PLUMULARIA, Lamarck. 
Gen. Char. Polypidom plant-like, rooted, simple or branched, 
the shoots and offsets plumous: cells small, sessile, unilateral, 
usually seated in the axillee of a horny spine ; vesicles scattered, 
unilateral. Polypes hydraform.—Dr. Johnston. 
* Stem a single tube. 
1. Prumutaria FatcaTa, Sickle Coralline, Merrit. 
(Plate VIII. fig. 22.) 
Hab. On shells and rocks near low-water mark, and in 
deep water. 
“This elegant feathered coralline adheres to rocks and 
shells by little wrinkled tubes, and rises from them into 
erect stems, which are surrounded from bottom to top with 
pinnated branches; the smaller divisions of these have rows 
of little denticles or teeth or cells on the side, and bend 
inwards, as they become dry, in the form of a sickle.” 
