68 SEA FISHERIES 



closely skirts the i,5oo-fathom line, after which the sea- 

 bottom rises and sustains the Canaries and the Cape 

 Verde Islands. To the west of the islands runs the 

 2,ooo-fathom line, marking the commencement of the 

 great Atlantic abysses. From the south of Morocco to 

 the neighbourhood of St. Louis in Senegal the region of 

 the continental plateau known as the Atlanto-Saharan 

 bank covers an area of 30,000,000 acres, or 48,000 square 

 miles, and the Baie du Lvrier (Greyhound Bay), which 

 forms an annex to the plateau, an area of some 250,000 

 acres, or nearly 400 square miles. 



The depth of water does not exceed 100 fathoms on 

 the plateau, or 12 fathoms in the bay. This bay, which is 

 bounded by Cape Blanco on the west, and lies open to 

 the Atlantic on the south, has the shape of an isosceles 

 triangle. On the eastern side the 2j-fathom line is a 

 long way from the shore from 2 to 4 miles but on the 

 western side it almost touches the beach, being only 400 

 or 500 yards distant. From the north to the south we 

 get the following soundings : i J, 2, 2j, 3^, 4, 5^, 6, 7, 6, 

 7, 7^, 5, and 3^ fathoms. To the right and the left of 

 this central line the soundings are to the east, from 3^ 

 to 6 fathoms ; on the west, 3}, 6, 7, 9^, 10, n, 7, 6, 8, 

 6, 5, and 7 fathoms. Finally, sailing from east to west 

 at the mouth of the bay we obtain the following sound- 

 ings : 3} (Cape Arguin), 2, 3^, 6J, 7, 8, 10, 6J (Grey- 

 hound Bank), 9, i2j, and 10 (Cape Blanco). 



To the north of Cape Blanco the Atlanto-Saharan 

 plateau presents four] natural zones. The first extends 

 4 miles out to sea from the shore ; the depth is from 2 to 

 2j fathoms ; it comprises hard shell sand, sand sprinkled 

 with the crests of emerging rocks, and, in the latitude of 

 Cape Blanco, a mixture of sand and ooze. The second 

 zone, which is only 2 miles wide, and slightly sloping, as 



