232 DAHLAK 



The red algae {Rodophyceae) also grow in these shallows, 

 represented by the genera Laurencia and Digenea (this latter 

 genus is more commonly represented by the species Digenea 

 simplex) . 



Among the single-celled algae is the Trichodesium ery- 

 thraeum, which in certain zones and at particular seasons 

 covers wide areas of the surface with an orange-red veil. 

 The sea has taken its name from this phenomenon. We came 

 across it ourselves on two occasions: the first time in the 

 channels and interior of the Ghubbet Mus Nefit of Dahlak 

 Kebir, in February, and the second time over a greater area, 

 near the island of Sciumma at the tip of the Dankal peninsula 

 of Buri, in April. The algae were spread over the surface of 

 the sea and in some places were heaped up by the currents to 

 a depth of inches, in appearance opaque and gelatinous. The 

 water underneath was a normal colour and clear. 



