KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 25. N:0 5. 15 



Class. II. CHLOROPHYLLOPHYCE^E (Rabh.) Wittr. 



Cohors 1. CONJUGATjE, De Baby, 1858. 

 Ord. I. DIATOME.E, Kutz. Phyc. Germ. p. 54, 1845. 



The Diatomea^ have not been at all critically examined, hut I have noted species of 

 the following genera: Diatoma, Navicula, Stauroneis, Pinnularia, and Synedra. 



Diatoms are not so plentiful in the gatherings as one might expect them to be, and 

 I think no great results will accrue when the species are determined in the Bengal col- 

 lection of Wallich; but in the micro-slides of material sent from two of Lagerheim's 

 habitats there appear some forms unknown to me, and these I shall be glad to submit 

 to a Diatomist. 



Ord. II. DESMIDIE.E (Kutz.) De Bary. 



Kutz. Syn. Diat. ex p. 1833; De Bary Couj. 1858. 



Gen. 1. Ancy lönerna, Berggr. 1871. 

 No form hereto appertaining has yet been seen out of high Northern latitudes. The 

 discovery of this species upon ice in the mountainous regions of the tropics would bo of 

 great interest. 



Gen. 2. Mesotaenium, Nag. 



Ti att. Einz. Alg. p. 108, 1849. 



1. M. chlamydosporum? De Bary (Conjug. p. 74, t. VIId; Palmogloea macrococca Kutz. 

 Tab. Phyc. t, XXIV, f. 2), forma. 



Long. 36—40, lat. 14 fx. 

 T. I, f. 3. 



2. M. Biaunii, De Bary (1. c. p. 74, t. VII a; Palmogloea macrococca, Al. Braun, Ver- 

 jiing. p. 349, t. I, II; non Kltz.). 



Long. 32, lat. 14 ,«. 

 » 42, » 20 » 

 T. I, f. 4. 



3. M. sp.? 



Long. 30-34, lat. 11 fi. 



T. I, f. 6. 



This form seems nearest to M. Endlicherianum Näg. (Einz. Alg. p. 109, t. VI b.). 



4. M. ealdarioruni (Lagerii.) Hankg. (Prod. Alg. Boehm. p. 174, 1888; M. Endlicherianum 

 var. caldariorum, Lagerheim in Bot, Not. p. 48, 1886; Wittr. et Nordst. Alg. Ex- 

 sicc. No. 850). 



Long. 31, lat. 12 u. 

 T. I, f. 23. 



5. M.? giganteum, n. sp. M.? permagnnm, regnlariter cylindricnm, 5 — 7-plo longius quam 

 latum; rectum vel leniter curvatum; membrana achroa glabra; apicibus rotundatis. 

 Cellula? libere natantes. 



