412 



broken , a thing which easily happens , specially if dried materials are 

 used for the examinations. With several species (for instance the plank- 

 ton Oscillatoriæ of which one has been examined by Richter) it is 

 difficult in dried materials to find undamaged trichomatas with calyptras, 

 as the trichomatas here are very frail, but with some care one will be 

 able to find them. And, is a character of less systematic value because 

 there is a difficulty in proving its existence from dead, dried up mate- 

 rials? Here 1 must specially accentuate, that the calyptras in all those 

 species of which I have examined living specimens, always were 

 perceptible and easily ascertained, but for the rest, the critical remarks 

 by Richter, only said in a footnote and with regard to one single 

 species, only are rather unimportant compared with the many facts 

 shown with great ability and care by Go mont in his studies on the 

 value of the calyptras as systematic characters. 



75. Anabaena torulosa (Garm.) Lagerheim. 



Bidrag till Sveriges algflora, in Öfversigt af K. Sv. Vet. Ak. 

 Forhandl., 1883, p. 47. 

 var. a, genuina. 



Sporis brevibus, diametro circiter duplo longioribus. 

 var. ß, longispora Nob. 



Sporis longissimis (diametro usqve ad 5-plo longioribus), 

 maturis in media parte evidenter constrictis. 



76. Anabaena baltica Nob. 



Libère natans. Trichomatibus evaginatis elongatis, valde 

 flexuosis et circinatis , saepius glomerulos parvos (ut in A. Flos- 

 aquae) formantibus, pallide aerugineis, 3 fx ad 4 p. crassis. Arti- 

 culis sphaerico-depressis vel ovalibus, 3 fj. ad h u longis, granulis 

 rubescentibus (ca vernis aëre repletis) farctis. Heterocystis sphae- 

 ricis vel subsphaericis parvis , 4 fi ad 6 fi crassis. Sporis rectis 

 ovalibus vel cylindricis brevibus, apicibus rotundatis, parce (2 — 3) 

 sériatis, heterocystis utrinqve contiguis , 10,8 p. ad 12 pt crassis, 

 19,6 fj. ad 24 p. longis, episporio laevi hyalino. 



Hab. in aqva subsalsa maris Baltici ad Gjedser insulae Fal- 

 ster inter alias algas phycochromaceas (Nodularia spumigena et 

 Aphanizomenon Flos-aqvae). 



The spores of this species found in the Baltic among other plank- 

 ton-algæ were mature at the end of august. 



85. Microchaete purpurea Nob. 



Algas majores (Fucos) incolens. T h all o maculiforme affixo, 

 purpureo, e multis caespitulis parvis dense congestis , saepius 

 seriatis formato. F i lis arete constipatis , rectis vel modice arcu- 

 atis, brevibus (vix usque ad Vs mm. longis), nunc erectis (in 



