VALONIACEiE. 
45 
less compressed, erect, coated with a velvetty scurf, and partially incrusted with cal- 
careous matter ; nearly destitute of lime when young, much incrusted with it in old 
age. This stipes is composed of innumerable, densely packed, longitudinal, unicellular 
fibres which closely adhere by lateral branching processes, and are interlaced together. 
The outer strata of these fibres emit, to form the periphery of the stipe, innumerable 
short, lateral, horizontal, multifid, fastigiate ramelli, whose apices, lying close together, 
give the velvetty appearance to the surface. As long as these longitudinal filaments 
cohere into a stipe they are unicellular ; but when they become free at the apex of the 
stipe, they are articulated, or pluricellular ; and a capitulum of confervoid filaments 
completes the frond. According to the age of the specimen, the filaments of the 
capitulum are more or less developed ; in young specimens they are less than an inch 
long ; in older and full-grown ones they vary from 3 to 6 inches. They are densely, 
but not intricately tufted, thicker than hog’s bristle, dichotomous, radiating to all 
sides, equal and obtuse ; their articulations are cylindrical, and many times longer than 
broad. The colour is a full, deep green, and they are very thinly incrusted with lime ; 
the crust pierced with minute pores. The primordial utricle separates readily from the 
cell-wall, and is firmly membranous. 
Plate XLIII. A, Fig. 1 , 2, 3. Penicillus dumetosus , of different ages: the 
natural sizes. Fig. 4. Portion of one of the dichotomous filaments of the capitulum-. 
Fig. 5. Small portions of the same, after the calcareous coating has been removed, 
showing a pitted surface ; the latter figures more or less highly magnified. 
2. Penicillus capitatus , Lamk. ; stipes long or short, cylindrical or clavate, terete, 
incrusted, smooth ; filaments of the globose capitulum densely crowded, fastigiate, 
capillary, rigid, pale green, their joints cylindrical, many times as long as broad, 
obtuse, constricted at the nodes. Dne. Cor. p. 97. Nesoea Penicillus , Lamour. Pol. 
flex. p. 258. Corallina Penicillus , Ell. and Sol. p. 126, tab. 25, fig. 4, 5. Corallo- 
cephalus Penicillus , Kiitz. Sp. Alg. p. 505. (Tab. XLIII. B.) 
Hab. Key West, W. H. //., Prof. Tuomey. (v. v.) 
Root very large, two inches long or more, deeply descending, very fibrous and 
densely matted. Stipes from one to four or five inches long, a quarter to a third of 
an inch in diameter, mostly cylindrical and equal throughout, occasionally compressed 
and widened upwards, thickly incrusted with calcareous matter, and having a smooth 
and sometimes a polished surface. Capitulum very dense, mostly globose, sometimes 
oblong and rarely somewhat diffuse, fastigiate, one or two inches in diameter, composed 
of innumerable, curved, densely packed and often entangled, capillary filaments which 
are encrusted with calcareous matter to an extent that makes them rigid. The 
structure is similar to that of the preceding species ; and the calcareous incrustation 
is similarly dotted or pitted. The length of the articulations varies much ; usually 
