F. Borgesen: Rhodophyceæ of the Danish W. Indies. 



129 



oQ9999HD\100Dnnr 



mm 



000 



Mal 



as broad or isodiametric ; towards the periphery the cells are, as 

 a rule, as high as broad or a little less. Seen from above the 

 peripheral cells have a diameter of d= 20 /m. The cells of C. Peys- 

 sonneliæjormis have a breadth of 20 — 12 fj. at the base, lessening 

 upwards to 8 and io b fi sX the top ; they are from IV2 to 4 times 

 as high as broad. 



The vertical rows of cells of C. Magdæ loosen themselves 

 from each other under very slight pressure after decalcification 

 and only their basal cells remain fastened together. This will 

 probably be in consequence of the 

 disappearance of the carbonate of 

 lime. There are lateral pores be- 

 tween the cellrows, but the pores 

 are very delicate and do not tend 

 to make the frond much firmer. 

 C. Peyssonneliæjormis has no carbo- 

 nate of lime between its cellrows, 

 which do not loosen themselves from 

 each other under slight pressure ; 

 the frond is soft and fleshy to the 

 touch after having been moistened. 



The tetraspores of C. Magdæ 

 are born in sori at the top of the 

 vertical cell-rows (Fig. 137); they 

 divide in a cruciate way, but the 

 divisions are often irregular and 

 sporangia with two and three spores 

 only, are not rare. They are covered 

 by a pretty firm cuticula, that seems 

 to tear off at maturity of the spores. 

 The sporangia have a height of 36- 

 16—20 jji. 



ODOn&SnW 



DO 



DDL 



Dato. 



Fig. 137. Contarinia Magdæ 

 n. sp. a. section through vege- 

 tative part of tliallus in full 

 growth, with the cells in the 

 higher part dividing repeatedly. 

 b. section through part of a 

 soruswith tetrasporangia at the 

 top of the filaments. (120:1). 



-40 fx and a breadth of 



Found in the "Sound" between St. Thomas and St. Jan by Dr. 

 Mortensen. 



Fa/77. 3. Squamariacece» 



By Mme A. Weber-van Bosse. 



When treating of the Squamariaceæ of the "Sealark" expedition, 

 I divided the Peyssonnelia into three subgenera: 1. Peyssonnelia 

 s. s. or Eupeyssonnelia with a hypothallus consisting in the main 

 of straight filaments, running close to one another in a horizontal 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1. (1916). 9 



