68 Sir W. Jardine on the Char. 



rent or so strongly marked towards the basal end of the scale. 

 The osteology of the head was still more convincing. The ge- 

 neral greater delicacy of the bones in the parr were still kept 

 up very distinctly. The opercule* forming the outer edge of the 

 gill-covers is much more rounded than in the trout, approaching 

 in this respect to the salmon ; in the trout the lower angle is de- 

 cidedly angular. The inter-ope rctile in the parr is longer and 

 narrower. The maxillary bone is broader at the posterior cor- 

 ner, but much shorter in the parr ; the vomer is much weaker ; 

 the bones or rays of the gill-covers are longer and much nar- 

 rower than those of the trout. The teething of the parr is weaker ; 

 the bone of the tongue longer, weaker, and not so broad ; the 

 under jaw much weaker, and the distance between its rami in 

 the parr about one-third less. These are the most conspicuous 

 distinctions, but every bone varies ; and not in one only, but in 

 the many specimens which I have lately examined, the distinc- 

 tions were the same, and at once to be perceived. In this state, 

 therefore, I have no hesitation in considering the parr not only 

 distinct, but one of the best and most constantly marked species 

 we have, and that it ought to remain in our systems as Salmo 

 salmulus of Ray. 



The easiest distinguishing marks to a person who has not 

 leisure to dissect them, are the great size of the pectoral fins, the 

 shortness of the maxillary bone, and consequent diminutive 

 gape, compared with the same sized trout, and the breadth be- 

 tween the rami of the lower jaw. 



8. Salmo alpimis or Char. — This was tlie only other species be- 

 longing to this family which was met with during the excursion, 

 but from the want of proper nets, many specimens could not he 

 procured. Those taken were the Salmo alpinus. It appears to 

 be in many of the northern lochs, but is only taken when coming 

 to the mouths of the rivulets in spawning season. They reach a 

 considerable size. These char appeared to be more exclusively a 

 night-feeding fish than any of those denominated trout. They 

 also feed near the bottom. In their stomach we found the re- 

 mains of aquatic insects, with a mass of digested matter, which, 

 if examined by the microscope, may have been found to contain 

 more minute food. 



• The names of the bones are taken from the osteological plates of Cuvier, 

 which should be kept as the key to such descriptions. 



