IV; DICTYOTACEJ^.— Taonia. lOf 



IV. TAONIA, /. Ag. 



Hoot coated with woolly hairs. Frond flat, ribless, vaguely cleft, reticulated ; the 

 surface-cellules equally distant, in the apices of the lacinia; in parallel or subdiver- 

 gent series. Concentric lines more or less evident. Fructification : linear, wavy, 

 concentric, superficial sori, on both surfiices 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 Uha atomaria, Good, and 

 Woodw., which has been variously referred to Zonaria, Dictyota, 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 Kiitzing's 

 genus, Spatoglossum, for these two, whose relation to T. J.tomar«a is rather doubtful. 



1. Taonia? Schroederi, J. Ag. ; frond decompoundly cleft, irregularly dichoto- 

 mous ; laciniaj broadly hnear, 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. Dictyota Schroederi, Kutz. Sp. Alg. p. 566. Aresch. 

 Ic. t. 9. Ulva Schroederi, Mart. Fl. Braz. p. 21, Ic. Select. 1, t. 2, /. 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 tlie general outline of its lacinise, 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 laciniaj 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 lacinice are rounded, and the 

 laciniae 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. 



p 2 



