No. 3] REMARKS ON NORTHERN LITHOTHAMNIA. 123 



even ten times the breadth. Their length is 30 — 90 fJ., generally 

 50 — 70 [*., their breadth 6—20 ,u, mostly about 12 //. The length 

 of the cells of the perithallium is twice to four times the breadth. 

 They are 18 — 45 p- long and of about the same breadth as the 

 cells of the hypothallium. I have not seen cortical cells like those 

 figured by Rosanoff, Rech. Melob. pi. IV, fig. 5. 



As to the synonymy it is to be observed that Melobesia 

 Cystosirce Hauck is partly referable to this species. I admitted 

 it in Lithoth. Adriat. Meer. p. 27 as a form of Litliopliyllum 

 papillosum. But as I stated in the note 1. c. p. 29, I afterwards 

 found that it partly also includes the alga in question, probably 

 both f. macrocarpa and f. australis. Therefore, it ought to be 

 omitted as a denominated species or form. 



Also Melobesia confinis Crn.. which I admitted as an indepen- 

 dent form under Litliopliyllum hapalidioides in Rem. Melob. Herb. 

 Crouan 1. c, is. partly referable to L. pustulatum on account of 

 what I have had the opportunity of seeing afterwards. As obser- 

 ved below, it is, however, almost impossible to draw any certain 

 line between L. pustulatum and L. hapalidioides. 



Melobesia pustulata Aresch. Obs. Phyc. 1. c. includes partly 

 f. Laminarice, partly Litliopliyllum Crouani Fosl. according to an 

 authentic specimen examined. 



In Rem. Melob. Herb. Crouan 1. c. I classed Hapalidium 

 confervicolum Toni et Levi, Phyc. Ital. no. 15 with Melobesia 

 confervicola (Kiitz.) without having seen any authentic specimen 

 of the latter. I observed, however, 1. c: „The species needs a 

 closer examination of better materials than that which I at present 

 possess". By the kindness of Prof. De Toni I have had the 

 opportunity of examining one more specimen of the Hapalidium 

 confervicolum distributed 1. c. The alga then proved virtually 

 representing a form of L. pustulatum-. The oblique basal cells 

 are about 36 \i long and 9 fi broad, and the perithallium is formed 

 by a single layer with the cells about 18 \i long and 9 fi broad. 

 The conceptacles are subconical and 250 — 300 fi in diameter. The 

 alga, therefore, must be referred to L. pustulatum. Though the 



