332 LAKE SUPERIOR. 



varies with the ground on *rhich it is caught. Those found on a 

 muddy bottom are generally grayish, while those from a gravelly bot- 

 tom are of a reddish color, with much brighter fins. The amethystine 

 color does not show itself distinctly while the fish is swimming, or 

 when first caught, but only after being taken from the water, when 

 the mucus on the surface begins to dry. The sexes differ in shape, 

 the male having a more pointed head than the female, although the 

 jaws are of equal length. The dentition, though somewhat stronger 

 than in the S. Siscowet, presents generally the same disposition. The 

 vomer especially has the same structure ; there is a row of teeth on 

 the hinder and rounded margin of the chevron, with a middle row on 

 the body of the bone itself. According to Dr. Richardson, there 

 should be here a double row of teeth. Probably in growing, they are 

 thrown out alternately and obliquely, and thus cause the row to 

 appear double. I should not know how to explain otherwise this 

 divergence, unless the disposition of the teeth upon this bone be sub- 

 ject to great variations, which seems not to be probable. The 

 description of Dr. Dekay is very obscure in relation to the teeth of 

 this species. He speaks of a double row of teeth on the vomer and 

 the palatines, which is an error, especially with regard to the latter. 

 When he says that they are in two series along the labials, of which 

 the outer is smaller and more numerous, he evidently speaks of the 

 palatines and upper maxillary together ; therefore, if the upper max- 

 illary and the palatines constitute in his view a single group (labials) 

 of two rows, the palatines cannot at the same time have a double 

 row. This description may have been copied without being under- 

 stood, like the figure itself, which is taken from the Fauna Boreali- 

 Americana. 



The small ossicles of the branchial arches are nearly straight and 

 denticulate on their outer margins, as in the Salmo Siscowet. The 

 bony shields of the pharyngeals are considerably developed, and the 

 teeth which cover them arranged like cards, and very prominent. 

 There is one behind the tongue, narrow and elongated ; another, but 

 somewhat smaller, which corresponds to it, on the vault of the 

 palate, and behind these two, and surrounding the large throat, two 

 upper and two lower pharyngeal shields. 



This species was mentioned by Pennant, towards the close of 



