- 177 — 



Forma spinis valde convergentibus. 



Long. 33 (jl: lat. sine spin. 29//; long. spin. 7 — 8 fi\ lat. isthm. 12/i. 

 On rocks in riverbed. 



Area: Europe, Siberia, India, Geyion, Java, Japan. 



83. S. echinatum Bréb. in Ralfs Brit. Desm. 1848, p. 215, t. XXXV, 



f. 24. 



Long, sine spin. 33 // , cum spin. 42 ju ; lat. sine spin. 29 p , cum 

 spin. 40 /i ; lat. isthm. 9 jul. (Tab. nostr. Ill, fig. 31). 



This Staurastrum of which we observed several examples, has been 

 referred to 8. echinatum Brèb. after much consideration. It is certainly 

 not a form of 8. teliferum Ralfs., neither is it a form of S. gladiosum 

 Turn., the only other species with which it could be confounded. Bré- 

 bisson's figure in Ralfs , British Desmids' (I.e.) is a very poor one, 

 and yet our plant agrees with it in size, in outward form, in the depth 

 of its constriction, and in relative length and number of the spines. 



From 8. teliferum Ralfs it differs in its somewhat rhomboideo-ellip- 

 tical semicells which cause a much more open sinus ; the spines are more 

 numerous, a little longer and more delicate; the angles of the vertical 

 view are not so rounded, the sides are hardly so concave, and the spines 

 are more scattered. 



From S. gladiosum Turn, it is distinguished by its somewhat smaller 

 size, by its relatively longer cells, its more angular semicells and slightly 

 more open sinus; the spines are about the same in number, but they are 

 slightly longer and more delicate, and are more or less evenly distributed 

 over the whole of the semicells; the angles of the vertical view are not 

 so rounded and the spines extend all over the central part (i. e. all over 

 the actual dorsal region of the semicells of the Staurastrum). 



The S. echinatum figured by Wolle (Desm. U. S. 1884, t. 45, f. 31 

 — 32) does not represent the species, the spines being too short. That 

 figured by Turner (in Kongl. Sv. Vet.-Akad. Handl. Bd. 25, no. 5, 1893, 

 t. VI, f. 48) may be a form of S. echinatum Bréb. but it does not agree 

 sufficiently well with Brébisson's figure in Ralfs , British Desmids' to 

 represent a typical specimen. The plant recorded by S c h m i die (in 

 Engler's Botan. Jahrbuch. Bd. XXVI, 1898, p. 55) as „St. echinatum forma?" 

 and figured by him (t. IV, f. 11) as „S. echinatum Bréb." is much too 

 short-spined for Brébisson's species and is much nearer a small form 

 of S. pilosum (Näg.) Arch. 



In stagnant water in the jungle. 

 Area: Europe, India. 



84. S. submonticulosum Roy et Biss., in Journ. Bot. 1886, p. 238, 

 t. 268, f. 7. 



Forma angulis propius ad basin semicellularum ; isthmo paullo angu- 

 stiori. 



Long. 28//; lat. 31^; lat. isthm. 8//. 



In stagnant water among other Desmids. 

 Area: Japan. 



12* 



