24 M. FOSLIE. [1905 



f. typica. 



Descr. Lilhoth. Sonderi Hauck 1. c. 



f. sublcevigata Fosl. mscr. 



Frond even or subeven and feebly shining; conceptacles of 

 sporangia 250 — 400 // in diameter. 



f. pacifica Fosl. 



New Sp. or Forms of Melob. (1902), p. 4; Setch. and Gardn. Alg. Northw. 

 Amer. (1903), p. 358! 



The form sublcevigata is distinguished for its even or almost 

 even frond, which is feebly shining. Besides, the conceptacles of 

 sporangia are frequently a little smaller than in the typical form. 

 It is perhaps only a local form, once found in the litoral region 

 in a much exposed locality at Rovser near Haugesund. I have seen 

 specimens also from the British Tsles which are almost even, but 

 they are dull and the conceptacles a little larger. Specimens from 

 there, growing on dead LitJwth. calcareum, sometimes are feebly 

 shining and rather resembling the form in question, but they are 

 young and stunted. However, the specimen from Finistere men- 

 tioned below seems to stand near to this form and is perhaps identic. 



As to the form pacifica 1 am still unable to draw any certain 

 line between this form and f. typica. The excrescences are more 

 regular than usually seen in European specimens, but in this respect 

 no limit is to be drawn. I have even seen specimens of this form 

 approaching f. sublaivigata in habit. The conceptacles of sporangia 

 also agree with typical L. Sonderi except that the roof frequently 

 is a little thicker. The sporangia too are of about the same size. 

 However, as remarked 1. c, antheridia and cystocarps are not yet 

 known in f. pacifica. Therefore, its relation to the species in 

 question in fact depends on these organs. 



In structure this species stands near to or almost coincides 

 with closely adherent forms of LitJwth. Lenormandi. However, 

 the hypothallium in the latter species is nearly always vigorously 

 developed, in a vertical section often occupying the greater part of 

 the thickness of the crust, whereas in L. Sonderi the said layer 

 is rather feebly developed. The cells are frequently 14 — 25 /->■ long 



