1925] SetcheU-Gardner: Melanophyceae 549 



(Menegh.) 8. and G. {Liehmannia Posidoniae Meneghini, 1843, p. 300, 

 pi. 5, fig. 1), M. zostericola (J. Ag.) S. and G. {Cladosiphon zostericola 

 J. G. Agardh, 1882, p. 43, pi. 2, figs. 3a., 36), and possibly M. erythraea 

 (J. Ag.) S. and G. (CladosipJwn erifthraeum J. G. Agardh, 1848, 

 p. 55). 



Meneghiniella Brandegeei S. and G. 



Plate 47, fig. 11, and plate -49, fig. 16 



Fronds very slender, soft and flabby, 8-16 cm. high, up to GOO/x 

 diam., irregularly and alternately branched, with branches coming off 

 at wide angles ; medullary filaments composed of large thin-walled, 

 colorless cells up to lOOfx diam. and several times longer than the 

 diameter, firmly agglutinated, becoming much smaller toward the 

 periphery ; cortical assimilating filaments simple, clavate, free, not 

 compact, more or less arcuate, composed of 7-12 moniliform cells ; 

 gametangia fasciculate with uniseriate loculi for the most part, 40-50/x 

 long, 7-lOjti diam. ; zoosporangia and hairs unknown. 



Habitat unknown. La Paz, Lower California. 



Setchell and Gardner, Phyc. Cont., VII, 1924, p. 5. 



The specimens on which this species, as well as the genus, are 

 founded are not as representative as could be desired, but the char- 

 acters are plain both as to the structure of the frond and the shape, 

 position, and the structure of the gametangia which can clearly be 

 determined. The tips of the filaments indicate trichothallic growth. 



FAMILY 12. HETEROCHORDAEIACEAE fam. nov. 



Main fronds erect, with main axis and lateral branches of limited 

 growth ; growth in length subapical as in the Chordariaceae ; axes of 

 three tissues: (1) medullary or central of elongated parallel, colorless 

 cells; (2) intermediate of shorter colorless cells, and (3) cortical of 

 short, anticlinal rows of colored cells, the distal cell being more or less 

 swollen ; zoosporangia and gametangia on full-sized, similar plants. 



It seems something like violent procedure to separate this family 

 from- the Chordariaceae, but the presence of full-sized gametangial 

 plants in this family and the lack of any such plants among the Chor- 

 dariaceae (as limited by us) is certainly significant, in view of the more 

 recent indications as to the relative characteristics of the gametophyte 

 and sporophyte among the Melanophyceae. 



