ICHTHYOLOGY. 



211 



Malacop- powerful motions in the water. Dr Richardson describes 

 its sides as tiiitjed with lavender purple, mixed with bhi- 

 ish gray, witiiout streaks ; the belly blackish gray, with 

 several irregular white blotches ; and there are five or six 

 longitudinal rows of uniform quadrangular spots of Prus- 

 sian blue on the anterior part of the body. There is a 

 large blue mark underneath the lower jaw on each side. 

 The dorsal fin, which forms a prominent feature in the 

 fish, is of a blackish-gray colour, with some lighter 

 blotches. Superiorly it has a narrow margin of light lake- 

 red, and posteriorly it is beautifully ornamented with 

 spots of Berlin blue. The ventrals are streaked with red, 

 and with whitish lines in the direction of their rays. The 

 scales are moderately large, and have no great lustre ; 

 their exterior margins are rotund and entire, or very slight- 

 ly undulated, those on the anterior part of the belly being 

 much smaller than the others. Of the fins the dorsal is 

 the most extraordinary, being, according to Dr Richard- 

 son, " probably by far the largest in this genus." Its co- 

 lours, as above mentioned, are beautiful, and, with its great 

 size, form the chief ornament of the fish. It contains twen- 

 ty-four rays ; the first two or three are small ; but the 

 others increasing rapidly in height, as their origin is more 

 posterior, become more and more branched, and cause the 

 fin to play loosely like a flag over the posterior part of 

 the body ; the insertion of the fin occupies about one third 

 of the length of the body, and the extremity of the poste- 

 rior ray, which is five inches long, reaches as far as the 

 adipose fin.' Specimens were taken sixteen inches in 

 length. Another American grayling, found in the same 

 northern localities, is the Thymallus tltymalloides, Cuv. ; 

 Coregonus tliymalhides, Richard. Resembles TIi. signi- 

 fer, but differs remarkably in the size of the dorsal fin. 

 The body is compressed, and of a bluish gray, with pur- 

 ple reflections when moved in the light. The dorsal fin 

 contains from twenty-two to thirty-four rays ; but the 

 posterior ones do not branch out in the same manner, and 

 scarcely exceed the others in height ; hence the fin has a 

 very different aspect. It is about one inch high, has a dark 

 bluish-gray colour, with several rows of spots, having pur- 

 ple centres and light-red borders. The usual length is 

 eight inches.- 



Genus Coregonus, Artedi. Distinguished from the 

 last by the still finer teeth, larger scaling, and small dor- 

 sal fin ; live in shoals in lakes or still waters, and only ap- 

 proach the edges during spawning time. Of delicate 

 structure; feed much on entomostraca, and aquatic insects 

 and their larvae. Flesh white and delicate. The best- 

 known British species is the Guiniad, or 



Cor. lavaretus, Salmo lavaretus, Linn. Frequent in the 

 lakes of Cumberland and Westmoreland, and also found 

 in some of the Scotch lochs, — for example, Loch Lo- 

 mond, where, as in the north of England, it is termed the 

 schelky. According to the best authorities, it likewise 

 occurs in those of Alpine and Northern Europe. It does 

 not reach a very large size ; the average may be stated 

 from nine inches to a foot in length. The colours chaste 

 and delicate, of a greenish gray above, changing to whit- 

 ish, with a silvery lustre. The scales are of considerable 

 size, and, when examined narrowly, are seen to be cover- 

 ed with minute black dots. It is used for the table, but 

 is not so delicate as our other British species. It is known 

 under the name oi fresh-water herrbig in most of its loca- 

 lities. 



Cor. marcBtiula, found in the Swiss lakes and some 

 other parts of the Continent of Europe, is a small species, 

 of nearly the same colours as the last. This fish was sup- 

 posed to be found in some parts of Britain, and the ven- 



dace of the Lochmaben lochs was thought referrible to it. 

 When Scotch specimens, however, were shown to Mons. 

 Agassiz during the autumn of ISSJ', he considered them 

 distinct from the species known to the continental Ich- 

 thyologists as C. 7narai7nda, and the title of C. WUbigh- 

 bii was suggested for the Scottish kind. Continental spe- 

 cimens of C. marcinula have not yet been received by us, 

 and the distinctions, therefore, cannot at present be detailed. 

 The vendace of Lochmaben, whatever scientific name it 

 may ultimately receive, or whether it may be identical or 

 not with the species inhabiting the lakes of Continental 

 Europe, may be described as an interesting example of 

 the genus. It is one of the most elegant, though of a 

 small size, reaching from four to ten inches in length. The 

 head is of an angular shape, and small compared %vith the 

 size and depth of the body. The crown of the head is 

 very transparent, and the form of the brain, which is 

 heart-shaped, is seen through the integuments. This 

 peculiarity is one of the first things pointed out to the 

 stranger naturalist who visits Lochmaben to see this spe- 

 cies. The eye is large and brilliant ; the body rises grace- 

 fully to the back fin, and recedes with a gradual line to 

 the tail ; the under line is nearly straight from the gills to 

 the ventral fin. The upper parts are of a delicate green- 

 ish brown, shading gradually into a clear silvery white ; 

 the dorsal fin greenish brown, the anterior edge much 

 lengthened and pointed ; the lower fins all bluish white ; 

 the tail much forked. They spawn about the commence- 

 ment of November. The roe is minute and abundant, and 

 of a bright orange colour. The flesh is white and rich, 

 and highly prized as food ; but as it requires almost to be 

 eaten on the spot, it is not useful as a market commodity 

 when transmitted to any considerable distance. The 

 lochs of Lochmaben are the only authentic British habi- 

 tat for this species. 



Several other species inhabit the Swiss lakes, and are 

 known chiefly from the works of the continental Ichthy- 

 ologists, particularly M. Jurine, who has devoted a paper 

 to the fishes of the Lake of Geneva. He there describes 

 C. fera and hyemalis (the latter so named from its ap- 

 pearing only in winter) ; and Baron Cuvier notices a third 

 from the Lake Neufchatel, under the title of C. palcea. 

 In America several species are found in the lakes and 

 rivers. The white fish of Dr Richardson seems to belong 

 to the genus. It is the C. albus of Lesueur, and is call- 

 ed by the Cree Indians Attihhawmegh, a name corrupted to 

 Tittameg by the traders. This fish attains a weight of 

 from three (the ordinary size) to twenty pounds. It 

 abounds in every lake and river, and is much esteemed 

 as food, in many parts forming the sole article of diet 

 for years together, without producing satiety. The sto- 

 mach is of great thickness, generally filled with earth 

 mixed with slender roots, and small white worms. It 

 spawns in October. Another species is C. quadrilateralis, 

 Richardson, of which the colour of the upper parts is in- 

 termediate between honey yellow and wood brown ; the 

 scales with a thin border of blackish gray round their ex- 

 terior margins ; the belly white, with a pearly lustre ; the 

 eye moderately large, the iris with a silvery hue ; the 

 mouth without teeth ; the fins are yellowish ; the adipose 

 fin attached for its whole length. The stomach not 

 thickened. The food small insects. Inhabits the Arctic 

 Sea, and the small rivers about Fort Enterprise. The 

 average size is about fifteen inches in length. 



Under this division also appears to rank the Inconnu of 

 Mackenzie and the Canadian Voyagers, although it is 

 placed by Dr Richardson in the genus Salmo, under the 

 name of S. Machenzii. We therefore here record it as 



Malacop. 

 terygii 



Abdorai- 

 nales. 

 Salmo- 

 nidas- 



' Eichardson, in the Appendix to Franklin's Juurucy to the Polar Sea, p. 711. 



Ibid. p. 714. 



