SALMONID^E. 125 



Genus III — Coregonus, Artedi. 



Argyrosomus, Agassiz (lower jaw the longer). 



Branchiostegals seven to ten : pseudobranchice well developed. Body somewhat 

 elongated. Cleft of mouth shallow : maxilla deep, and posteriorly not extending 

 to behind the orbits. Teeth, when present, minute and deciduous. First dorsal 

 fin with a moderate number of rays, the second adipose. Caudal forked. Scales 

 of moderate size. Air-bladder large. Pyloric appendages numerous. Ova small. 



Some authors have believed that the vendace, Coregonus vandesius, was 

 introduced into Lochmaben, Dumfriesshire, from the continent of Europe, 

 by or for the unfortunate Mary Queen of Scots. As the species has not been 

 recognized on continental Europe, is difficult to transport, while it is not 

 restricted to one Scottish loch, this tradition appears to rest on an uncertain 

 foundation. In aquaria a very little matter affects them, a trifling variation of 

 temperature, a little impurity or a difference between the oxygenating surfaces 

 of two tanks, Lloyd proved were matters of life or death. 



It has been questioned by some excellent authorities whether the species of 

 this genus may not have been unduly multiplied, and M. de la Blanchere (Diet, 

 des Peches) observed that after a special study made at the Imperial establishment 

 at Huningen, where he had fishes of all ages under observation, he had come 

 to the conclusion that either the genus Coregonus ought to be composed of many 

 distinct species, these distinctions being based upon fugitive and little marked 

 characters : or else, that a single species is present endowed with great 

 variability.* 



Geographical distribution. — Mostly found in lakes, a few periodically migrating 

 to the sea, in the northern portions of temperate Europe, Asia, and North 

 America : while some appear to be marine. There are numerous species, several 

 being found living in a single lake. In North America, under the term of " white 

 fish," they are captured throughout the fresh waters. Dr. J. Davy observed that 

 the vendace and skelley are rarely taken by anglers, or any way except by the 

 net, and are of comparatively little value. It cannot be supposed that man ever 

 took the trouble to place the skelley in a tarn such as the Red-Tarn, situated 

 under the brow of Helvellyn, many hundred feet above Ullswater, and so 

 difficult of access. Much the same reflection presents itself as regards the 

 vendace in Derwentwater and Bassenthwaite Lake, taking into account the 

 distance of these lakes from Loch Maben. 



Synopsis of Species. 



1. Coregonus oxyrhynchiis.—T) . 14-15, A. 14-15, L. 1. 75-80, 7§ rows of scales 

 between the lateral-line and the insertion of the ventral fin. Snout soft and 

 produced into a conical form. Marine entering fresh water. 



2. Coregonus clupeoides. — D. 13-15, A. 13-16, L. 1. 73-90, 7£ to 8 rows of 

 scales between the lateral-line and the insertion of the ventral fin. Snout 

 vertically truncated. Fresh waters of the Lake districts and also of Wales. 



3. Coregonus vandesius. — D. 11, A. 13-14, L. 1. 66-70, seven rows of scales 

 between the lateral-line and the insertion of the ventral fin. Lower jaw the 

 larger. Fresh- water lochs of Scotland. 



4. Coregonus pollan. — D. 13-14, A. 12-14, L. 1. 80-88, nine rows of scales 

 between the lateral-line and the insertion of the ventral fin. Jaws anteriorly 

 of equal length. Fresh waters of Ireland. 



* Collett (Norges Fiske) considers as pertaining to C. lavaretus, C. murcBna, Bloch, 

 C. Widegrenii, Malmgr. G. lapponicus, Giinther, 0- gracilis, Giinther ; also probably C. 

 maxillaris. Giinther, and C. humilis, Giinther. 



