COLLINS. — THE ALGAE OP JAMAICA. 241 



Spring; on sand at edge of river, Castleton, April, 1893, No. 

 364, H. 



Hormothamnion enteroraorphoides Grunow. In shallow water, St. 

 Ann's Bay ; on coral reef, Navy Island, July 25, 1897, H. P. B.-A., 

 No. 56. Near Kingston, Duerden. 



*Scytonema Arcangelii Born. & Flah. On moist rocks by spring, 

 Castleton, April, 1893, H. 



S. conchophilum Humphrey ms. In old conch shell, Port Antouio, 

 March, 1893, H. Kingston, June, 1897,11; Producing slight, gray, 

 pustular roughenings of outside of shell, Mastigocoleus testarum occur- 

 ring on inside of same shell. 



Filaments 5-8 /x diam., irregularly branched, branches single or gemi- 

 nate, tips rounded, cells two thirds to two times as long as broad, 2.7- 

 4.5 fx diam., pale bluish when separate. Heterocysts globose or slightly 

 elongated, 5 /x diam., rarely two or three together, intercalary. Sheath 

 rather thin, deep yellow, homogeneous ; when old, rough outside, hyaline 

 and thin at growing tips. J. E. Humphrey. 



*S. crispum (Ag.) Bornet. On sides of trough, Constant Spring; in 

 basin, Kingston, April, 1893, H. P. B.-A., No. 60. 



*S. densum (A. Br.) Bornet. In turfs, moist places, Port Antonio, 

 April, 1893, H. 



*S. Hofmanni Ag. On steps of Court House, Port Antonio, April, 

 1893, H. 



*S. Javanicum (Kuetz.) Bornet. On flower-pot in garden, Castleton, 

 April, 1893, H. 



*S. ocellatum (Dillw.) Thuret. On old palm stems, Castleton, April, 

 1S93, H. 



*Hapalosiphon fontinalis (Ag.) Bornet. • On rock, " Wag Water," 

 Castleton, April, 1 893, H. 



Mastigocoleus testarum Lagerh. In old shells, Kingston, 1897, H. 



Calothrix aeruginea (Kuetz.) Thuret. On Dasya arbuscula, Montego 

 Bay, June, 1900, P. & B. 



C. confervicola (Roth) Ag. On various algae, Port Antonio, March, 

 1893, H. 



C. Contarenii (Zan.) Born. & Flah. On wreck on beach, Port Mo- 

 rant, March, 1893, H. 



*C. fusca (Kuetz.) Born. & Flah. Among Gloeocapsa quaternata, 

 Bath, 1900, P. & B. 



*C. Juliana (Meneg.) Born. & Flah. On stones in stream, Roaring 

 River, St. Ann's Bay, March, 1893, H. 



VOL. XXXVII. — 16 



