IV. 
DICTYOTACEJL— Taonia. 
107 
IV. TAONIA, J. Ag. 
Root coated with woolly hairs. Frond flat, ribless, vaguely cleft, reticulated ; the 
surface-cellules equally distant, in the apices of the laciniae in parallel or subdiver- 
gent series. Concentric lines more or less evident. Fructification : linear, wavy, 
concentric, superficial sori, on both surfaces of the frond, destitute of indusium, and 
consisting of spores , furnished with hyaline perispores, and unaccompanied by 
paranemata. 
This genus is formed for the reception of the old TJlva atomaria , Good, and 
Woodw., which has been variously referred to Zonaria , Dietyota, and Padina. To 
this typical species, whose character is chiefly embodied in the above generic 
diagnosis, Prof. Agardh has added, doubtfully, two other species, one of which falls 
within our limits. Perhaps it would have been better to have retained Kutzing’s 
genus, Spa toglossum, for these two, whose relation to T. Atomaria is rather doubtful. 
1. Taonia? Scliroederi , J. Ag. ; frond clecompoundly cleft, irregularly dichoto- 
mous ; laciniae broadly linear, toothed above, and bordered with marginal processes 
or lobules; “antheridia? scattered over the whole surface,” (fructification unknown). 
J. Ag. Sp. Alg. vol. 1, p. 102. Dietyota Scliroederi , Kiitz. Sp. Alg. p. 566. Aresch. 
Ic. t. 9- Ulva Scliroederi, Mart. FI. Braz. p. 21. Ic. Select. 1, t. 2, f. 3. 
Hab. At Vera Cruz, Mexico, Liebman! (v. s. in Herb. T.C.D.) 
Frond rising from a shaggy base, ten to twelve inches in length, somewhat fan. 
shaped in tire general outline of its laciniae, irregularly dichotomous ; the principal 
laciniae from half to three-quarters inch in breadth, the upper ones gradually 
narrower. In the lower part of the principal lacunas the margin is either entire 
or obscurely denticulate ; in the upper half it is either strongly toothed, or the 
teeth lengthen out into linear or subulate, simple or slightly compound lobules. 
Sometimes the margin is flat, sometimes undulated or even curled. The apices are 
often irregularly jagged. The sinuses between the lacinias are rounded, and the 
lacinias themselves diverge at wide angles. The substance is thin and mem- 
branous, shrinking much in drying ; and the colour is a brownish or a greenish 
olive. No fructification has yet been observed, but the frond is commonly dotted 
over with minute, dark, prominent cells, which Agardh supposes may contain 
antheridia. 
