1919] Setchell-Gardner : Myxophyceae 73 



3. Trichomes 1 5-2/i. thick 3. L. Willei (p 74) 



4. Sheaths finally j-ellow brown 4. L. aestuarii (p 75) 



4. Sheaths always hyaline 5 



5. Trichomes 9-25/u. thick, apices never attenuate-capitate 



5. L. confervoides (p 77) 



5. Trichomes 5-12/i. thick, apices often attenuate-capitate ...6. L. semiplena (p 78) 



Section 1. Leibleinia (Kuetz.) Gomont 



Filaments caespitose, fixed when submerged, attached by the cen- 

 tral portion and intertwined, erect at both ends ; sheaths thin, hyaline, 

 not evidently lamellate ; trichomes not attenuated at the apices ; marine 

 species of the aspect of Calothrix. 



Gomont, Essai Class. Nost. Horn., 1890, p. 354; Kuetzing, Phyc. 

 Gen., 1843, p. 221 (as genus, char. mut. et sp, excl.). 



The species referred to the subgenus Leibleinia are epiphytic, 

 attached at the middle and free at both ends. They seem to be wholly 



marine. y /Ar i n t? t 



1. L. gracilis (Menegh.) Kab. 



2. L. cpiphytioa Hieron. 



3. L. Willei S. and G. 



1. Lyngbya gracilis (Menegh.) Rab. 



Tufts extended, dense, floecose, slippery, purple violet, often losing 

 color on drying and becoming dirty yellow, up to 1.5 cm. high ; fila- 

 ments elongated, flexible, angularly flexuous ; sheath thin, smooth, does 

 not turn blue with chlor-zinc iodine; trichomes rose-red, torulose (in 

 dried specimens), 5-8ju, thick, not attenuated at the apices; cells quad- 

 rate or twice shorter than the diameter, 2.8-4.6/a long; protoplast 

 finely granulate ; apical cell rounded, with the membrane slightly 

 thickened above. 



On Chaetomorpha aerea in pool. Pacific Beach, southern California. 

 Mrs. M. S. Snyder. 



Rabenhorst, F\. Eur. Alg. II, 1865, p. 145 ; Gomont, Monogr. des 

 Oscill., 1892, p. 124 (1893, p. 144, Repr.) ; Collins, Ilolden and 

 Setchell, Phyc. Bor.-Amer. (Exsicc), no. 853. Leihleinia gracilis 

 Meneghini, Alg. Spec. Nov., 1844, p. 304 {fide Gomont). 



The only specimen known to us is that mentioned above, dis- 

 tributed as no. 853, in the Phycotheca Boreali-Americana. It is cer- 

 tainly of the subgenus Leibleinia and seems to be very close to L. 

 gracilis so far as answering to the description is concerned. The 

 determination is l)y Frank S. Collins. It is accompanied by other 

 epiphytes. 



