rikssted. At St. Thomas and St. Jan I have often dredged in 

 the sea round Water Island especially in Gregorie Channel, 

 further in the Sound between St. Thomas and St. Jan, where a 

 very rich algal vegetation was found. On the whole the sea 

 round St. Jan has appeared to be very rich both on the north 

 side where I have dredged along most of the coast until near 

 the east end and on the south side until near Rams Head. 



In the sea surrounding these islands no very great depth 

 occurs, the deepest part is about 20 fathoms. But on the other 

 hand rather deep water, up to ten fathoms or more comes often 

 quite near the steep, rocky coast; this applies especially to the 

 exposed north side of these islands. In the larger and smaller 

 bays we have shallow water with sandy or muddy bottom often 

 covered with mangroves f. i. the extensive mangrove growth in 

 the Bovoni Lagoon at the east end of St. Thomas. 



St. Croix on the other hand has the greater part of the coast 

 surrounded by coral reefs and shallow water, the only exception 

 from this being the northwestern rocky coast, where the great 

 oceanic depths come quite near. But the sea is most often very 

 turbulent and I have therefore not been able to dredge there. 



An opportunity of trying to dredge in greater depths and 

 on the whole of examining to what depth the algse are able to 

 grow, was afforded me when the Ministry of Marine gave me 

 permission to go out with the cruiser »Ingolf«, but the result 

 was negative, as the dredge immediately caught in the rocky 

 bottom and was lost. 



When mentioning some of the most important external 

 conditions under which the algse live at the shores of the Danish 

 Islands I may yet point out that the tide is nearly wanting and 

 in every case of no practical significance to the algse ^). 



The greater part of my collection has been dried but of 

 nearly all the gatherings I have also had material preserved in 

 alcohol or formaline and the examination has nearly always 

 been based upon this. 



Of earlier contributors to our knowledge of the algse of 

 the Danish West Indies Rector Hans West may first be men- 

 tioned. West collected algse and sent them to Professor Martin 

 Vahl who has described several of them iri his paper: »Endeel 



^) Regarding the external conditions of life to the algse compare also 

 my above quoted paper concerning the Gaulerpas and as to the algal 

 vegetation in the lagoons also my treatise in )>Biologiske Arbejder 

 tilegnede Eug. Warming*, Kobenhavn 1911, p. 41. 



1* 



