Jordan and Evermann. Fishes of North America. 519 



ThytnaUits tricolor, COPE, Proc. Ac. Nat. Sci. Phila., 1865, 80, Au Sable River, Michigan ; 



GCNTHER, Cat., vi, 201, 1866; MILNER, Eept. U. S. Fish Comm., n, 1872-73 (1874), 739, and of 



late writers on angling generally. 



ThymaUus signifer tricolor, JORDAN & GILBERT, Synopsis, 303, 1883. 

 Tltyiitallns xiynifer iitarit'Hsi, JORDAN, Bull. U. S. Fish Comm., x, 1890, 49. 



Represented in the head waters of the Missouri by another isolated colony, 



788a. THYMALLUS ONTARIENSIS MONTANUS (Milner). 

 (MONTANA GRAYLING.) 



Depth 5^* in length, as in other forms; scales 99, and (in specimens exam- 

 ined) a little different in color. Dorsal dusky green, its posterior part 

 with three rows of bright-orange spots, faintly ocellated, irregular in 

 position, some of the spots oblong and placed obliquely ; above this one 

 regular row of similar spots, extending obliquely across the fin from end 

 of second third of anterior ray to tip of last ray ; fin edged with bright 

 orange-brown. Entirely similar to the Michigan Grayling, but the dorsal 

 a little smaller. Madison and Gallatin rivers, very abundant in springs 

 and small streams on the west side of the Yellowstone Park, ascending 

 streams as far as Firehole Falls and Gibbon Falls. 



Thyniallns montanus, MILNER, Kept. U. S. Fish Comm., 11, 1872-73 (1874), 741, tributary of 

 Missouri River at Camp Baker. (Type, No. 13090. Coll. J. Scott Olclmixon.) 

 signifer montanus, JORDAN & GILBERT, Synopsis, 303, 1883. 



Family LXVI. ARGENTINID^S. 



(THE SMELTS.) 



Body elongate, covered with moderate or small scales, which are usually 

 cycloid. Head naked. Mouth terminal, small or large, formed as in the 

 Salmonidce, the maxillary forming the margin of the upper jaw. Teeth 

 various, sharp-pointed. Gills 4, a slit behind the fourth. Gill mem- 

 branes separate, free from the isthmus, with 6 to 10 branchiostegals. 

 No barbels. Stomach a blind sac, with the pyloric coeca few or none. 

 Dorsal fin short, nearly median ; adipose fin always present ; caudal 

 forked ; anal moderate ; pectorals placed low ; ventrals moderate, nearly 

 median ; no spines in the fins. Lateral line present. No phosphorescent 

 spots. Abdomen rounded. Air bladder large, single. Ova large, falling 

 into the cavity of the abdomen before extrusion. Small fishes, marine or 

 anadromous, some of them inhabiting deep waters ; all but one genus 

 confined to the waters of the Northern Hemisphere. There are about ten 

 genera and perhaps a dozen species ; reduced Salmonidce, smaller and in 

 every way feebler than the trout, but similar to them in all respects 

 except the form of the stomach. Most of them are \ery delicate food- 

 fishes, and the species of Thaleichthys is, in this respect, preeminent 

 among our fishes. (Salmonidce, part, Gunther, Cat., vi, 166-172, 203-205, 

 1866.) 



a. Branchiostegals 6 to 10; body not cylindrical, the sides more or less compressed; gill mem- 

 branes separate. 



* Not 4% as stated by Milner. 



