COREGONUS VANDESIUS. 351 



Its favourite spawning- ground is a hard rocky bottom. The female fish 

 is rather the larger. The stomach is found to contain the small bivalve shell 

 Pisidium, the fry of Stickleback, Entomostraca, and Limnaa, besides larvae of 

 insects, and the freshwater shrimp, Gammarus. 



The species varies a little in proportions in the different lakes. The, length 

 of the head is equal to the depth of the body, which is about one-sixth of the 

 total length of the fish. The eye is one-quarter of the length of the head. 

 The jaws are equal in length ; both may have a few delicate teeth, and the 

 teeth are chiefly seen on the tongue. 



The lateral line descends a little at the opercular region, and then runs 

 straight to the tail. There are eight longitudinal series of scales between the 

 lateral line and the ventral fin. The colour of the upper part of the body is of 

 a dark blue, the sides and abdomen are silvery. The dorsal, caudal, and anal 

 fins are dark, with finely-diffused pigment. Nearly all that is known of this 

 species is due to its original discoverer. 



There are sixty to sixty-one vertebra?. 



Coregonus vandesius (RICHARDSON). The Vendace. 



D. 11, A. 13, V. 11. Scales : lat. line 6871, transverse 



The name Vendace, according to Pennant, is derived from the French 

 Vandoise (Dace) which the Scottish fish resembles in the whiteness of its 

 scales ; and in Scotland the tradition runs that it was introduced in the time 

 of Mary Queen of Scots. As the fish does not occur on the Continent, it is more 

 probable that the Continental taste of the Frenchmen about her Court for fresh- 

 water fishes may have brought it into notice, and provided it with a name by 

 which it is now identified. It is found in the lochs near Lochmaben in 

 Dumfriesshire, and also in Windermere and Bassenthwaite, and comes 

 down the Annan to the Sol way Firth. 



Sir William Jardine states that the constitution of the fish is so deli- 

 cate that it is quite unable to bear transport. In habit it nearly resembles the 

 Powau ; they both swim in large shoals and are taken only with the net. 

 They make their way against the direction of the wind, and on dull days are 

 readily captured near the shore of the loch, but during warm and clear 

 weather retire to deep water, better able apparently to accommodate them- 

 selves to the increased pressure than to the increased temperature. The Ven- 

 dace feeds on Entomostraca and other minute forms of life. It spawns in 

 October and November, and then often jumps out of the water into the air. 

 The females are larger and more numerous than the males. 



