96 



spines. A vert. 5-radiate; at the base of each ray, on the left side, 

 a strong horizontal spine. Long. 20- 25 p. ; lat. cum rad. 40-48, sine 

 rad. 12 a. 



S. hìcornutum n. sp. p. 290, f. 9. Semic. subhexagonal, top some- 

 what rounded; angles prolonged, each into a ray with three or four 

 serrations, and apex trifid. At base of each ray on the upper side 

 a stout forked spine. Above and between these two smaller ones 

 below the end of the semicell. A vert. triangolar, the angles pro- 

 longed into serrate rays; two forked spines projecting beyond the 

 margin on each side, with six smaller ones within the margin, for- 

 ming a circle around the center. Dim. 14-16 « (cum rad.) 22-26 » 6 [j. 



S degantissimuni n. sp. p. 290, f. lò. Semic. nearly square. Con- 

 striction shallow. Base of semic. armed with a row of short spines, 

 sometimes with traces of a second ; angles prolonged into stender 

 slightly incurved rays armed with three spines at apex. Rays armed 

 above and on each side with a row of sharp spiny teeth, several 

 nearest the base bifurcate. A vert 4 radiate; within the margin on 

 each side a row of several incurved bifurcate teeth, the two rows 

 on opposite sides of the ray uniting into a median one near the 

 middle of the ray. Long. 36-38 p; lat. e rad. 68 72, s. rad. 16-18 v.\ 

 isthm. 12 V. 



Ausserdem werden Formen folgender Arten abgebildet: Xanthidìum 

 anlilopaeum v. Miniieapoliense Wolle (W. et G. S. Wesl Some N. 

 Amer. Desm. in Trans. Linn. Soc. London Voi. 5, Part 5, p. 253, 

 nennen Johnson's Form v. Johnsoiiii), Staurastriim leptocladum Nordst. 

 [W. et G. S. West, 1. e. p. 266, machen aus Johnson's Form cine 

 neue Art, S. JohnsoniiJ und var. cornutum Wille, S. irregulare West, 

 Cosmarium cyclicum Lund., C. impressulum Elfv., C. subglobosum 

 Nordst., C. sulcatum Nordst., C. calcareum Wittr. (Cfr. West « Some 

 recently pubi. Desm » p. 4, in Journ of Bot. 1895', C. lessellatuni 

 Nordst. und Onychonema leve v. inicracanthum Nordst. 



C. biocidatimi Wolle Desm. Un. St Tab. 18, fig. 22 ist nach 

 der Ansicht des Verf. cine Form von C. tenue Arch. (cfr. Nordst. 

 hidex Desmid. p. 61). 



17- Kirchner 0. XXIX. Sijsswasser-Algen (Ber. d. Comm. f. d. 

 Flora V. Deutschl. 1891 in Ber. d. Deutsch. bot. Ges. Bd. X. Berlin 

 1892) 9 pag. 



Enthàlt tur Deutschland angegebene neue Desmidicen und neue 

 Fundorte schon bekannter. 



18. Knowiton, F. H. Dircctions l'or collectintjr recent and fossi! 



