32 Dansk Botanisk Arkiv, Bd. 2. Nr. 2. 



jedem fortwachsenden Spross ein centraler Leitfaden, eine ächte 

 Centralachse, das Spitzenwachsthum vermittelt. Diese monopodial 

 fortsprossende Centralachse bildet nach allen Seiten aus ihren 

 Gliederzellen Zweiglein, die theils langsamer, theils rascher heran- 

 wachsen''. This short quotation shows clearly the differences 

 that exist as in my plant I have always found several filaments 

 in the growing point, and these filaments had a sympodial growth. 



On the other hand the growth of my plant seems to agree 

 well with that which M me Weber found in the plant referred by 

 her to Bactrophora nigrescens 1 ). M me Weber has given a very 

 detailed description and beautiful figures of its method of growth. 

 In response to my request M me Weber has also been so very 

 kind as to allow me to examine her plant and having compared 

 it with the mine I cannot deny that upon the whole it has much 

 resemblance. The specimen I saw was sterile but M me Weber has 

 found unilocular sporangia. In this connection I wish also to draw 

 attention to that which Prof. Kuckuck has written in a review 2 ) 

 of M me Weber's paper: "Die Identifizierung einer Mesogloeacee 

 als Bactrophora nigrescens erscheint dem Ref., der die HARVEY'sche 

 Originalpflanze untersuchen konnte, sehr zweifelhaft. Das bei 

 der malayischen Pflanze beobachtete sympodiale Wachstum kann 

 er für andere Mesogloeaceen bestätigen". 



My plant was only found once in a somewhat sheltered 

 place in shallow water ; it was growing epiphytic upon the leaves 

 of Thalassia testudinum. 



St. Croix: At the estate Lt. Princess behind Long Reef. 

 Geogr. Distrib. Atlantic coast of Europe and North America. 



Fam. 4. Myrionemacece. 

 Myrionema Grev. 



1. Myrionema spec. 



Upon an old Padina a small disc-shaped alga was found 

 which showed much likeness to Myrionema, e. g. to forms of 

 Myrionema vulgare as figured by Sauvageau in his paper treating 

 of the Myrionemaceæ. 



The disc in this specimen increases by means of marginal 

 growth ; seen from above it is found to be composed of horizontal 

 filaments, radiating from the centre, being now and then dichoto- 

 mously divided. 



') Weber- van Bosse, A., Liste des Algues du Siboga, I, 1913, p. 139. 

 -) In "Zeitschrift für Botanik, 6. Jahrg., 4. H., 1914, p. 361. 



