— 183 — 



the innerside of the membrane-cells. The cells in the filaments 

 are nearly cylindrical or somewhat thicker in the middle, about 

 20^ thick and 5 — 8 times as long. 



Only tetrasporic plants occurred. The tetrasporangia are devel- 

 oped in the bark-layer. (Fig. 2 D.) They are cruciately divided and 

 rather small, about 27/^ broad. 



This species has been found in deep water (12 — 16 fathoms) 

 in the Sound between St. Thomas and St. Jan near the Island 

 Gr. St. James and in the sea to the north of St. Jan: off America 

 Hill, where it was collected by Dr. Th. Mortensen and myself, 



Chrysymenia ventricosa (Lamour.) J. Ag. 



J. Agardh, "Algge maris Mediterr. et Adriat." 1842, p. 106. 

 Dumontia ventricosa Lamour., "Essai Thalassioph." 1813, p. 45, 

 tab. 10, fig. 6. 



Fig. 3. Chrysymenia ventricosa (Lamour.) J. Ag. 

 A, membraue-cells seen from the innerside; the cells in the middle with glands (70:1). B, trans- 

 verse section of the membrane (70 : 1), C, filaments growing out from the innerside of the mem- 

 brane-cells in about the middle part of the thallus (125:1). 



