IV. 
DICTYOTACEflE. — Zonaria. 
105 
spores , each containing four sporules in the perispore ; fig. 5, section through one 
of the concentric bands of paranemata ; fig. 6, paranemata : the latter figures 
more or less highly magnified. 
III. ZONARIA, Ag. 
Boot coated with woolly hairs. Frond flat, ribless, coriaceo-membranaceous, 
flabelliform, entire or vertically cleft, the segments radiating ; the surface cellules 
disposed in distinct longitudinal lines flabellately radiating from the base. Con- 
centric lines indistinct. Fructification roundish or linear sori, formed beneath the 
cuticle of the frond, and bursting through at either surface ; and composed at 
maturity, of spores furnished with hyaline perispores, and of p>aranemata which are 
mixed with the perispores. Paranemata club-shaped, articulated, numerous. 
In the more or less fan-shaped frond this genus approaches Padina , but differs in 
the more opaque substance, only obscurely marked with concentric zones ; and in 
the fructification, which is not disposed in regular, concentric lines. Here, too, 
the spores and paranemata occupy the same sorus, while in Padina they are sepa- 
rated. Under a pocket lens the surface appears to be finely striated longitudinally ^ 
an appearance caused by the disposition of the superficial cellules, which are ranged 
in lines proceeding from the base, slightly diverging one from another, and admit, 
ting the introduction of new series of cells between each original row, as the frond 
advances in growth. From this peculiarity results the fan -like form of the mature 
frond. 
Ten or twelve species of this genus, from various parts of the world, are known 
to botanists. All are natives of the warmer parts of the sea, with the exception of 
Z. parvula , which by some authors is rejected from the genus. 
1. Zonaria lobata , Ag. ; frond erect, coated with woolly hairs at the base only, 
membranaceo-coriaceous, broadly flabelliform, at first with a nearly entire margin, 
then palmately cloven, or divided nearly to the base ; lacinias eventually elongate, 
wedge-shaped, simple or again divided, concentrically zoned ; sori linear, formed 
along the concentre lines. J. Aq. Sp. Alq. vol. 1, p. 109. Stypopodium fuliqinosum , 
Kiitz. Sp. Alg.p. 663. (Tab. YII. C.) 
Hab. On stones about low-water mark. Annual ? Keys of Florida : abundant 
at Sand Key in February ; and sparingly, at the same season, at Key West, W. H. H. 
Sand Key, Profi. M. Tuomey. (v. v.). 
vol. ru. art. 4. 
p 
