articulis compresso-diseiformibus, distinetis. Sporae . . . 
— Habitat in Potamogetone crispo. 
8, J. moniliformis Borzi. Trichomata tenerrima, 
 solitaria vel pauca, muco amorpho mox evanescente involuta, _ 
irregulariter aggregata, ad apices sensim attenuata, laxe 
sinuosa aut incurvata, caerulea, subhomogenea; artieulis 
_ vegetativis transverse ellipticis, distinctibus; apicalibus sub- 
lobosis, paullo minoribus. Sporae globosae, intense ceaeru- 
leae (?). — Habitat in rivulis. 
4. J. infusionum Borzi. (Anabaena inf. Kütz., A. 
mieroscopica Menegh.) — 
Die systematische Uebersicht der Nostochaceae gestaltet 
sich nach Borzi folgendermassen: 
5 Tribus 1. Isocysteae Borzı. ; 
Trichomata cellulis perdurantibus (heterocystis) destituta, 
muco parcissimo involuta, in thallum irregulariter diffusum 
 densissime et paralleliter aggregata, raro subsolitaria. 
Genus 1. Isocystis Borzi. 
Genus 2. Aphanizomenon Morren. 
ne; Tribus 2. Nostoceae Borzi. ee. 
 Trichomata cellulis perdurantibus praedita, gelatina 
 copiosissima plus minus firma aut diffluescente involuta, m 
'thallum varie expansum saepissime indefinitur implicata, aut 
_  _ raro muce citissime soluto, subsolitaria. 
. .* Sporae globosae, ovales vel ellipticae, absque ordine 
ee Nostoc Delpini Borzi (pag. 281.) 3 
Thallo mediocri, irregulariter expanso-bullato-tuberculato; 
trichomatibus tenuibus dilute olivascentibus laxe implicatis, 
flexuosis vel eircinatis; artieulis oblongo-cylindraceis, 2—2 Y 
‚quam latis, aretissime connexis; cellulis perdu- 
bus elliptieis, subduplo majoribus; sporis oblongis aut 
ticis, fusco-olivaceis, exosporio minutissime granulato- 
to, apieibus truncatis, laevibus. Habitat in locis 
