428 
Scytonema crispum (Ag.) B. & F. This species, known as 
Scytonema cincinnatum or Lyngbya cincinnata, although not credited 
to North America by Bornet and Flahault, is probably not un- 
common in the Eastern United States. Wolle had it from Penn- 
sylvania or New Jersey, as is evidenced by a specimen in the 
writer's possession. Mr. Isaac Holden has found it near Lanes- 
ville, Conn.; Mr. W. J. V. Osterhout finds it in abundance near 
Providence, R. I.; Mr. Wesley R. Coe, in Florida; Dr. J. E. 
Humphrey, in Jamaica, W. I., and the writer about New Haven, 
Conn. The filaments vary very much. Sometimes both branches 
and heterocysts are rare and the species looks very much like a 
Lyngbya, very often the scanty branches occur single and adjacent 
toa heterocyst and it resembles greatly a 7Zolypothrix, while the 
geminate branches midway between two heterocysts, characteristic 
of Scytonema are generally found only after long and careful search. 
Scytonema Javanicum (Kuetz) Bornet, one of the species with 
erect branches agglutinated into Symploca-like fascicles and pre- 
viously credited chiefly to the tropics (Java, Brazil and Guyana), 
but also found in France, according to Bornet and Flahault, reap- 
pears in this country in small quantity, growing on the trunks of 
trees in Middlesex Fells, Melrose, Mass. : 
Hassallia byssoidea Hassall is a very variable species and is 
credited to South Carolina only in this country by Bornet and 
Flahault. A form of it, not exactly typical, grows on rocks at the 
water’s edge along the Quinebaug River in Lisbon, Conn. It 
forms small tufts nearly black in color. It is characterized, a5 4 
form, by its regular, erect branches given off at an acute angle. 
Desmonema Wrangelii (Ag.) B. & F. is a curious genus of the 
Tribe Scytonemaceae, characterized by having several filaments 
inclosed in a common sheath and also by having basal heterocy Sts 
It is very abundant in Roaring Brook, a mountain rivulet 10 
Cheshire, near New Haven, Conn. It grows upon stones and 
rocks in the swiftest currents and forms slippery, bluish black ex- 
pansions. On being detached from the substratum it falls apart 
into small penicillate tufts. It is present during the month of 
June at least. 
Nostoc parmelioides Kuetz. is one of the most readily recog” 
nized species of the genus. The frond is erect and attached at 
