220 



114. C. Schubelerii Wille. Plate VII, fig. 7. 



Formå færoen sis a formå typica præcipue difFert magiiitudine 

 celkilæ paullo majore, apice semicellularum medio non retuso sed 

 late rotundato-truncato; a vertice visæ apicibus latioribus. 



Long. = 121 |M ; lat. = 102 /« ; lat. isthm. = 27 ju ; crass. = 54 ia. 



I have only seen a few specimens of this species, but unfortu- 



nately the structure of the chlorophyl was indistinct. It seems to 



me to be very much like C. Ralfsii Bréb. (Ralfs Brit. Desm. tab. 15, 



fig. 3) but it differs from it in the more broadly truncate apices of 



the semicells and in the cells being greater in breadth in proportion 



to their length. 



This species was only found in a very rich gathering from Kirkebo- 

 kamp near Thorshavn (Str.). 



115. C. Cucurbita Bréb. 



Ralfs 1. c. tab. 17, fig. 7. 



Long. = 22 |M. 



Occurs in gatherings from Trangisvaag (Syd.); Tliorsliavn, Kirkebo- 

 kamp, Hojvig and Skjælling iStr.l. 



116. C. pachydermum Lund. 



Tlie specimens from tlie Færoes wliicli I liave placed under 

 this species are all much smaller, their dimensions answer to those 

 which Nordstedt gives for the var. minus Nordst. Norges Desm. p. 18, 

 but with regard to the outline of the cell the specimens from the 

 Færoes come nearer to the typical form. 



Long. = 52-62 fA ; lat. = 38—40 fi. 



Ivalso; Tliorshavn (Str.); Sand (S an do). 



117. C. perforatum Lund. var. rotundata nov. var. Plate VII, fig. 6. 

 A formå typica var. rotundata differt, cellulis fere circularibus, 



apice semicellularum medio tantum vix truncato, incisura mediana 

 acutissime angulata extrorsum sensim dilatata; membrana distincte 

 punctata, medio ad bases semicellularum crassiore scrobiculis mi- 

 nutis (a vertice visibilibus!) instructa; a vertice visæ semicellulæ 

 subhexagonæ-ellipsoideæ. 



Long. = 71 ,m; lat. = 60; lat. isthm. = 33/«; crass. = 38 jm. 



In a gatliering from Sand (San do). 



This variety seems to resemble verj' closely the form described by Boldt in 

 iDesm. från Gronland« p. 14; also in vertical view the specimens from the Færoes 

 are slightly ssubhexagona«. 



