Jordan and Evermann. Fishes of North America. 513 



In aureolus the pectorals are shorter (1% in head) and the dorsal lower than in alpinus. In 

 the latter the pectoral is 1% to \% in head. 



Other apparent differences which may depend wholly or in part on the condition of the speci- 

 mens are these: The hyoid (hypobranchial) teeth in aureolus are smaller and in a broader series 

 than in alpinus, the stomach a little thicker and the pyloric coeca smaller. I doubt the constancy 

 of these characters. The specimens of aureolus are also a little more robust in form, a character 

 of trifling value among trout. 



Dr. Day has recently maintained, and he has shown good cause for his opinion, that the six or 

 eight nominal species of charr ascribed to the waters of Great Britain are all forms of one Salvelinus 

 alpinus. Recent continental writers seem to share this view, long ago advanced by Agassix, who 

 placed all the charrs of Europe, including Iceland, in a single species, alpinus. Dr. Day has 

 shown that the species is subject to great variation in the development of the pectorals. None of 

 the European writers has paid much attention to the gill rakers. Dr. Giiuther has counted in 

 English specimens 9 and 11 gill rakers on the lower limb. If these counts are correct, the 

 number would vary from 6 + 9 to 9 + 15. But this count may be questioned, as it is not unlikely 

 that some of the smaller ones have been omitted in Dr. GUnther's enumeration. When all these 

 facts are taken into consideration, the only character left to distinguish the Sunapee charr from 

 the saibling is the curved form and perhaps lesser number of its gill rakers. 



This problem is complicated by the existence of other saibling-like charrs in lakes of Canada 

 and Greenland. It is evident, too, that some of these are even more like the saibling than the 

 Sunapee trout is, a fact which Dr. Bean has already pointed out in a letter to me. 



The specimen abo've mentioned from Disco, Greenland, is a fine trout, 15 inches long, wholly 

 silvery in color, a fact which shows that it was taken in the sea. This specimen has the gill 

 rakers slender and straightish, 9 -f 15 in number, the longest 2% in eye. In this respect it agrees 

 perfectly with the saibling, but in the form of the body and the shortish fins (the pectoral 1% 

 in head) it more resembles the Sunapee trout. This Greenland fish represents the species called 

 Salvelinus nitidm (Richardson). This has been thought to be simply the female of a long-finned 

 Greenland trout, called Salvelinus stagnalis (Fabricius). Perhaps nitidus is the female and stagnalis 

 the male, or perhaps stagnalis is based on river and nitidus on sea-run specimens. Apparently 

 the two are not distinct species and I do not see how either can be separated from alpinus. 

 Apparently, also, nitidus only differs from aureolus in having the gill rakers of alpinus. An unpub- 

 lished engraving of another Greenland trout (nilidus) agrees perfectly in form and color with 

 aureolus, but the gill rakers are not shown. 



In view of all these facts, I have no hesitation in regarding these Greenland charrs as forms 

 of the saibling. That the saibling should extend its range across to Greenland need not surprise 

 us. It is found in all the mountain lakes of Europe from Austria toSpitzbergen. It enters the 

 northern seas and swarms in the ponds of Iceland. In late autumn, in the North Pacific, black- 

 spotted trout (Salmo mykiss) and the Dolly Varden charr (Salvelinm malma) freely enter the ocean, 

 and they inhabit alike both sides of Bering Sea. The saibling could as easily reach Greenland 

 from Iceland as to cross to Iceland from the Scottish coasts. 



Two other specimens before us are also of interest in this connection. One of these, a young 

 trout, 10% inches in length, with parr marks and without red spots, is from a lake near Quebec. 

 The other, 9% inches long, was taken in the Gulf of St. Lawrence. This specimen is very dark 

 in color, almost like a blueback. It has no red spots and its scales have the silvery luster which 

 is acquired on entering the sea. [These belong to the form since described as Salmo marstoni, 

 Garman; previously recorded by Dr. Bean as Salvelinus rossi.] 



These two specimens seem to agree with each other in essentials. They have straightish 

 gill rakers like the saibling, but their number of these appendages (7 + 12 and 7 + 14) is inter- 

 mediate between the saibling and the Sunapee trout. The pectoral fins are also intermediate in 

 length, lg in head in one specimen, If in the other. The opercular bones seem more straight 

 than in any other specimens examined, but this appearance may be due to the fact of the partial 

 drying of the skin over the bones before the fish was put into alcohol. These specimens are 

 apparently intermediate between the saibling and the Sunapee trout, and again intermediate 

 between the Greenland nitidus and the Sunapee fish. The specimen from Quebec agrees in all 

 respects, waiving nonessentials, with Dr. Giinther's figure of Salcelinus arcturus, the "northern- 

 most Salmonoid known," from the northern limit of British America. Dr. Bean has suggested 

 to me that this specimen may be the unrecognized Salvelinus rossiof Kichardson. This view may 



F . N . A. 34 



