497 



It has been observed in May and .lune and probably also 

 lalcr (cfr. Siinmons, 1. c. p. 272), and foiind with • zoospores in 

 the same months. 



Found in the following piaces: — Bordo: Klaksvig ! ; Ost.: Ejde ' . 

 Vaago: MidvaagØ); Str.: Thorshavn (!); Naalso(!);? Syd.: Klaksvig 

 Simmons). 



ULVA (L.). 



169. U. Lactuca L. Lyngb., Hydrophyt., p. 30; Kjellman, N. I., 

 p. 361 (293). 



A transverse section ol" the thailus shows that the cells vary 

 much in form, being sometimes short, about as long as broad, 

 sometimes long and narrow, and in this the latter examples coine 

 very near to Ulva crassa Kjellm. (I. c. p. 29,'}); one of my reasons 

 for mentioning this here is, thai Simmons (1. c. p. 273) regards 

 some speeimens gathered by him in Trangisvaagljord as belonging 

 unquestionably to the latter species. I have not seen S im mons's 

 speeimens, but it appears to me that my speeimens should pro- 

 perly be re fer red to Ulva Lactuca, with which species Ulva crassa, 

 as Kjell mann himself (I. c.) also pointed out, is very closely allied. 



Lyngbye (Le.) describes a var. (I contorta of this species as 

 follows: — »fronde basi attenuata, spiraliter contorta, crassa, deinde 

 in plures lacinias dilatatas profunde lissa«. His herbarium contains 

 a specimen from Thorshavn. 



This species occurs in the sublittoral zone and is met with 

 from about low-water mark down to a depth of some 10 fathoms. 

 In N. I., Kjellman savs that this species grows in the littoral zone 

 along the Norwegian coasts of the Arclic Sea and it is conse- 

 quently perhaps, possible that it also occurs littorally along the 

 coasts of the Færoes. It has been found on sheltered as well as on 

 exposed coasts and grows on rocks and stones and more rarely as 

 an epiphyte on larger algæ. Large vigorous piants occurred from 

 Mav to December, and fruiting examples from May to July and 

 in October. 



Tliis species is quite conimon along the coasts of the Færoes. 



Order ULOTHRICACEAE. 



ULOTHRIX Kfttz. 



170. U. flacca (Dillw.) Thur. Rosenv., Grønl. Havalg., p. 935; 

 Wille: Studien iiber Chlorophyceen, p. 18, tab. I, ligs. 54 — 57, tab. II, 



