180 MESSRS. W. WEST AND G. S. WEST ON 
t. 16. fig. 15. Staurastrum Renardi, Reinsch, var. congruum, Racib., 1900. 
S. Hantzschii, Reinsch, var. depauperatum, Gutw., 1802. S. intricatum, Delponte 
(ex parte). 
Hab. With the preceding species. 
285. STAURASTRUM LEPTACANTHUM, Nordst. in Vidensk. Medd. naturh. Foren. Kjóbenh. 
1869, p. 229, t. 4. fig. 46. 
Long. sine proc. 24-36°5 u, cum proc. 44-67; lat. sine proc. 14:5-22 u, cum proc. 
38-544; lat. isthm. 9°5-13°5 u. (Pl. 21. figs. 29, 30.) 
Hab. Paddyfields, Heneratgodha. 
The specimens observed from Ceylon varied greatly in size and all possessed 15 
processes on the semicell, 9 in the inferior and 6 in the superior whorl. In this they 
resembled the form of S. leptacanthwm described and figured from Florida, U.S.A. 
(cf. West & G. S. West, ‘Some Desm. U.S., in Journ. Linn. Soc., Bot. xxxiii. 1898, 
p. 319, t. 18. fig. 12). 
S. tohopekaligense, Wolle, 1885 (syn. S. nonanum, W. B. Turn., 1893), is a species which 
very closely resembles S. leptacanthum, Nordst. It exhibits the same variability with 
regard to the number of the processes in the upper and lower whorls, and the typical 
forms of each species possess long smooth processes which are deeply bifurcate. 
S. leptacanthum has more globular semicells and a much broader isthmus than 
S. tohopekaligense, and the processes are relatively a little longer and more delicate. 
The vertical view of S. leptacanthum is always subcircular in outline, whereas that of 
S. tohopekaligense is always triangular (or rarely quadrangular). 
S. japonicum, W. B. Turn., is merely a form of S. leptacanthum, with slightly shorter 
processes which are not so deeply bifurcate. 
236. STAURASTRUM TOHOPEKALIGENSE, Wolle, 1885 ; Freshw. Alg. U.S. 1887, p. 45, t. 59. 
figs. 4, 5. S. nonanum, W. B. Turn. in K. Sv. Vet.-Akad. Handl. xxv. 1893, no. 5, 
p. 119, t. 15. fig. 14. 
Wolle's figures of this species do not represent the plant very well, those of Turner 
(under the name of S. nonanum) being much nearer the actual plant, American 
specimens of which we have observed in material received from the late Rev. Francis 
Wolle. We give a figure of the vertical view of one of these American specimens (Pl. 21. 
fig. 26). S. tohopekaligense exhibits a certain amount of variation in size, in the form 
of the body, and in the length of the processes. There are two whorls of processes on 
each semicell, the lower whorl consisting either of three processes (one at each angle) or 
of nine processes (one at each angle and a pair on each lateral margin), and the «pper 
whorl consisting of six processes. Thus the total number of processes on each semicell 
may be either nine or fifteen. Each process is very slightly dilated at the end and is 
always bifurcate. 
Schmidle suggested (in Engier’s Bot. Jahrbüch. xxvi. 1898, Heft 1, p. 52) that 
S nonanum should be placed as a variety of S. tohopekaligense, but as it does not 
differ in any respect from Woiles species we fail to see how he would define the 
variety. 
