Staiwastrum ' \i. desmidi lce e I \\ 
Hi [lla. — In uliginosis editioribus prope Hun,: 
Lopnllo ; May I860. No 15. Etiatn Morro de LopolL 
N,.. 182 
This Sl(iin-tis1riii„ belongs t < » the same section as 9. i 
Roy & Bias, and >. -i u >ar Nordst., but is ren distinct from 
either. Each of the three angles of the semi-cells is more or Less 
quadrate with a short bifurcate process -it the two upper o 
with an emarginate wart at each of the lower corners, and a Bhorl 
Btoul spine between the two emarginate warts. 
6. S. tridens-Neptuni W. el <;. 8. Wesl in Joui 
p. 177, t. 369, l'. 7. 
Builla. — Preq. in paludibus exsiccandis ; April I860. No 178 
l.tiani inter Utricularian . .Mono de Lopollo : April I860. No. 179- 
The near&st species to this is S. ubtrifurcatum W. el Or. S. W '• - 
[in Trans. Linn. Soc. 2nd ser. v. 258 9, t. \vi. f. •_' I (1896) |, from 
which it is distinguished by the three diverging and somewhal 
spines at each angle being situated in a vertical plane, and in th< 
pentagonal vertical view with acute angles. 
7. S. pentateuchophorum W.it G. S. Wesl in Journ. Bot. 1897, 
p. 178, t. 369, f. 6. 
Builla. Freq. in paludibus exsiccandis; April I860. No. 176. 
Etiam freq. inter Utriculariam, Morro de Lopollo; April 
No. 179. 
This species is somewhat allied to S. tridens-Neptuni, but is very 
distinct from it. 
8. S. heteroplophorum W. et G. S. Wesi in Journ. Bot. 1897, 
[i. 17s, t. 369, F. 8. 
Builla. — Freq. in paludibus exsiccandis; April I860. No. 176. 
Etiam inter Utriculariam, Morro de Lopollo ; April L860. No. 179. 
The arrangement of the spines on the much narrower angl 
seen in vertical view) easily distinguishes this species from > //■ 
E&alfs. At each angle there are two large spines in a vertical plane, 
and about six much smaller ones round them : the latter are some- 
times regularly disposed in a circle round the two larger ones. 
Var. latum W. el G. S. West in Journ. Bot. 1897, p. 178, 
t. 369, f. 9. 
Hi ii. i. a. —In paludibus exsiccandis ; April L860. No. 176- 
9. S. Pseudohystrix \V. el G. S. West in Journ. Bot. 1897, 
p. L78, t. 369, F. 10. 
Hi ii. i \. In paludibus exsiccandis ; April I860, No. 176. Etiam 
inter Utricular . Morro de Lopollo; April I860. No. 179. 
This species differs from S. Hystrix Kail's in its Bmaller Bize, its 
more angular Bemicells, its Fewer, longer, thinner, and curved Bpines 
which are confined to the face of the truncate angl< B. 
10. S. Welwitschii W. ei G. S. Wesl in Jouru B 
p. 179, t. 369, F. 1. 
Hi [lla. — In paludibus exsiccandis ; April I860. No. 176. 
This is a very characteristic Bpi ci( B. 
11. S. Corbula W. el G. S. Wesl in Journ. Bot. 18 1 
i. 369, f. 2. 
