340 MR. S. L. GHOSE ON A COLLECTION OF 
21. LYNGBYA CIRCUMCRETA, G. S. West, Journ. Linn. Soc. London, xxxviii. 
1907, p. 174, pl. 9. fig. 7; var. GELATINICOLA, var. nov. (PI. 31. fig. 7.) 
Strato sordide æruginoso ; filamentis in muco nidulantibus, in spiram con- 
tortis, spiris usque ad 100 y latis et interdum eum anfractibus 20 vel pluribus ; 
vaginis tenuissimis; trichomatibus angustis, cirea lp crassis, fragilibus, 
ærugineis ; articulis subquadratis, plerumque diametro brevioribus; dissepi- 
mentis sæpe distinctis ; apicibus rotundo-truncatis, 
Hab. Lahore, oceurring in a gelatinous stratum, adhering to the walls of 
drains, along with species of Closterium ; October 1919. 
This variety differs from the type in its non-planktonie habit and its much 
broader spirals with more numerous coils. 
22. SYMPLOCA MURALIS, Kütz. ; Gom., Monog. Oscill. 1893, p. 112, pl. 2. 
hg. 10. 
Alt. fasc. — ad 3 mm. ; diam. trich.= 35-4 y. 
Hab. Lahore, on damp walls of drains ; November 1919. 
23. SYMPLOCA MUSCORUM (Ag.), Gom. tom. cit. p. 110, pl. 2. fig. 9. 
Alt. fasc, 2ad 7 mm. ; diam. trich.= 5-6 u. 
Hab. Simla, on wet rocks or damp exposed roots of trees; August- 
October. 
21. MICROCOLEUS VAGINATUS (Vauch.), Gom. tom. cit. p. 355, pl. 14. 
fig. 12. 
Diam. trich.= circa 5 a. 
Hab. Lahore, commonly occurring on moist ground, generally on clayey 
soil, also on the soil in flower-pots ; most of the year. 
25. MicrocoLevs CHTHONOPLASTES, Thuret ; Gom. tom. cil. p. 353, pl. 14, 
figs. 5-8. 
Diam. trich.— circa 3 a. 
Hab. Lahore, on moist ground ; March 1919. 
In my material there were relatively few threads in the bundle, which 
probably marks a young condition. In other respects the alga is quite 
typical. The existence of saltpetre in the soil of Lahore is probably 
responsible for the presence of this species, which is mainly found in marine 
or brackish habitats. 
NOSTOCACEE. 
26. Nostoc MUSCORUM, Agardh ; Born. & Flah., Revis. des Nostoc., in 
Ann. Sci. Nat. Bot. ser. VII., vii. 1888, p. 200. 
Diam. cell.= 45-5; long. cell.= 5-7 u; diam. heterocyst.= 6-7 u; 
diam. spor. = 4-8 a; long. spor. = 7-10 p, 
Hab. Lahore, on moist ground, generally intermingled with species of 
Gleocapsa; August-March. 
