80 I". hoHGESEN. 



and tlie only oiu' dT wliicli 1 have st'cn a great luiiuijer ol' specimens. 

 It seems to be rather variable as to size and form of the cell. Most 

 of the individuals seen quite agreed ^vith the above-cited figure of 

 NoRDSTEDT, the cells being quite circular. 



Long. - 62// = lat. 



Other specimens were more hexagonal, coming near to the form 

 which Hoi.DT in Desm. Grønl., p. 23, tab. I, (ig. 24 has called var. 

 subarcticuiu. 



Long. = 67,«; lat. = 70 /i. 



This variety seems to come rather near to Cosm. Nordsiedtianum 

 Reinsch, which Nordstedt in "Hedwigia", 1876 has referred as a 

 form to Cosm. cycliciim (cfr. W. West and G. S. West, Monogr. of 

 the Brit. Desm., vol. II, p. 146, pi. LVIII, fig. 12). 



Loc. Danmarks Havn; Vester Elv. 



6. C. Debaryi Arch, in Pritch. Infus., p. 735. 



Borgesen, F'erskvandsalg. Ostgrønland, p. 21 (Hekla Havn). 



fi Novæ Semliæ Wille, Ferskvandsalg. Nov. Senilja, p. 48. 



The form observed seems lo agree quite well with forma minor 

 Wille, I.e. tab. XIII, fig. 47; but as I have only found a single spe- 

 cimen without chlorophyll I may mention that the determination 

 is not at all certain. Perhaps we have to do with a form of C. Cu- 

 cumis Ralfs (cfr. Nordstedt, Desm. arct. p. 29, tab. VIII, fig. 28, 29) 

 or with a big form of C. quad rat urn Ralfs. 



Long. == 90/^ ; lat. = 47 /^; lat. isthm. 31 a. 



The specimen was found in Vester Elv. 



Loc. Danmarks Havn. 



7. C. granatum Bréb. in Ralfs, Brit. Desm. p. 96, tab. 32, fig. 6. 



Boldt, Desm. Grønl. p. 12 (Knng Oskars hamn). 



Børgesen, Ferskvandsalg. Østgrønland, p. 18 (Hekla Havn). 



Larsen, Freshw. Alg. East Greenl. p. 85 (Kordlortok, Aniaka). 



Loc. Hvalrosodde. 



8. C. hexalobum Nordst., Desm. Spetsb., p. 33, tab. VII, fig. 16. 



Børgesen, Ferskvandsalg. Østgrønland, p. 15 (Hekla Havn). 



Larsen, Freshw. Alg. East. Greenl. p. 85 (Kap Dalton, Liverpool Kj'st in Hurry Inlet). 



This arctic and alpine species has been found in 

 several collections from Vester Elv. The form observed 

 (Fig. 2) agreed rather well with Nordstedt's description, 

 the only difference being that it was not quite so broad. 

 Boldt in Desm. Grønl. p. 24 has also mentioned such 



Fig.2. C.hexa- ^ "^rrow form. 

 lobum Nordst. Long. = 54«; lat. = 37//; lat. isthm. = 14. 



(""'i-) Loc. Danmarks Havn. 



