522 Bulletin 47, United States National Museum. 



241. OSMERUS (Artedi) Linnaeus. 



(SMELTS.) 



Osmerus (ARTEDI) LINNAEUS, Syst. Nat., Ed. x, 1758, 310, (eperlanus). 

 Eperlanus, GAIMARD, Voy. Island and Greenland, 1851, (eperlanus). 

 Spirinchus (JONSTON) JORDAN & EVERMANN, new subgenus, (thaleichthys). 



Body elongate, compressed. Head long, pointed. Mouth wide, the 

 slender maxillary extending to past the middle of the eye ; lower jaw 

 projecting; preorbital and suborbital bones narrow. Maxillaries and 

 premaxillaries with fine teeth ; lower jaw with small teeth, which are 

 larger posteriorly ; tongue with a few strong, fang-like teeth, largest at 

 the tip; hyoid bone, vomer, palatines, and pterygoids with wide-set 

 teeth. Gill rakers long and slender. Branchiostegals 8. Scales large, 

 loose, 60 to 70 in the course of the lateral line. Dorsal small, about mid- 

 way of the body, over the ventrals; anal rather long. Vertebrae about 40. 

 Pyloric coeca small, few. Small fishes of the coasts of Europe and North- 

 ern America, sometimes ascending rivers; delicate in flesh and consid- 

 erably valued as food, (bonrjpbc; , odorous ; the name is equivalent to the 

 English "smelt.") 



SPIRINCHUS (An old name used by Jonston for the smelt ; equivalent to spirling and eperlan) : 

 a. Vomer with a cross series of small teeth ; small, weak species spawning in the sea. 

 6. Body not very slender, the depth 5% in length ; commissure of mouth curved. 



THAtEICHTHYS, 791. 



bb. Body very slender, the depth 6 in length ; commissure of mouth nearly straight. 



ATTENUATUS, 792. 

 OSMERUS : 



aa. Vomer with 2 to 4 strong, fang-like teeth ; species stronger in habit, ascending rivers. 

 c. Scales rather small, 66 to 68 in lateral line. 



d. Maxillary not reaching posterior margin of eye ; depth 6 to 6% in length ; colora- 

 tion plain. MORDAX, 793. 

 dd. Maxillary reaching posterior margin of eye ; depth 5% in length ; coloration 

 brilliant. DENTEX, 794. 



Subgenus SPIRINCHUS, Jordan & Evermann. 

 791. OSMERUS THALEICHTHYS, Ayres. 



Head 4|; depth 5; eye longer than snout, 4 in head. D. 9; A. 14 to 

 16 ; P. 11 ; scales 55 to 58. Body comparatively deep and compressed. 

 Head rather short and deep, the maxillary broad, short, its edge 

 strongly curved, extending to opposite posterior margin of pupil; pre- 

 maxillary on the level of upper part of pupil ; mandible projecting, its 

 tip somewhat curved upward. Fins high, the pectorals usually reaching 

 ventrals, and the ventrals to anal; anal reaching about to caudal. Teeth 

 weak; maxillary teeth scarcely visible. Olivaceous, sides silvery and 

 somewhat translucent. Length 9 inches. Pacific coast from San Fran- 

 cisco northward to Bristol Bay in Alaska ; rather common ; a weak and 

 feeble species; its flesh of excellent flavor, but soft and not keeping well. 

 (Thaleichthys, the Eulachon, a related species of similar flavor as food.) 



Osmerus thaleichthys, AYRES, Proc. Gal. Ac. Nat. Sci., 1860, 62, San Francisco ; GUNTHER, Cat, 

 vi, 168, 1866 ; JORDAN & GILBERT, Synopsis, 292, 1883. 



