OYSTER AND MUSSEL REPORT. 127 



the case of Arcachon and of Les Sables d' Olonne there is 

 a sheltered inland sea, with a narrow entrance through 

 which the tide runs in and out with a considerable cur- 

 rent. The temperature of this water I found to be 66 °F., 

 and the specific gravity 1*025 to 1*026, practically that of 

 the open sea. In this area there are oyster pares for elevage. 

 No production of spat takes place here, the young oysters 

 being mostly obtained from Auray, a little to the north, 

 when about two years old and 5 or 6 cm. in diameter. 

 The pares contain abundant vegetation, the same green 

 algse being apparently present as those I found at 

 Marennes, and similar "green" oysters are produced 

 in some of the pares, although they are perhaps not so 

 well known as those from the estuary of the Seudre. 



I examined the pares at Croisic at low tide, and photo- 

 graphed one set of 12 quadrangular areas, each about 30 

 yards by 15 yards, separated from one another by a double 

 row of stakes supporting planks, the space between these 

 palings — about 2 yards across — being filled in with mud 

 and gravel. The stakes are placed about a yard apart. The 

 pare contains about 2 feet of water and there is a sluice at 

 one end of each enclosure. The walls between adjacent 

 pares are of this great thickness (2 yards) because there is 

 no stiff clay here like that which makes such excellent 

 enclosures at Arcachon. Ambulances with wire net lids, 

 like those at Arcachon, are also in use here for the very 

 small oysters. There are also great salt and oyster-rearing 

 excavations near to at Le Poulignen, and also between 

 Le Croisic and Le Bourg-de-Batz as shown in the accom- 

 panying sketch-plan (PI. Ill, fig. 3). The more irregular 

 areas shown in the left foreground and in the distance on 

 each side of the watcher's house are oyster pares, while the 

 very regular areas in the centre are for the manufacture 

 of salt. Mussels are also cultivated here both in beds and 



