522 Bulletin ^7, United States National Museum. 



241. OSMERUS (Artedi) Limueus. 

 (Smelts.) 



Osmeniis (Artehi) LiNNa-:us, Syst. Nat., Eii. x, 1758, 310, {eperlanvs). 

 Eperhdiiia, Gaijiard, Vov. If^laiiil ami GncnlaiKi, 1851, {eperhiuiis). 

 Sinrinclius (Jonston) .Jordan & Evkrmann, now subgenus, {thtilfichthya). 



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

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

 projecting; preorbital and 8nl>orbital bones narrow. Maxillaries and 

 premaxillaries with fine teeth; lower jaw with small teeth, wliich 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 co^ca 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, (liafjrjpn^, odorous; the name is equivalent to the 

 P2nglish "smelt.") 



Spirinchus (An old name used bj- Jonston for tlie smelt ; equivalent to f:pirling and cperlan) : 

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



b. Body not very slender, the depth 5}-^ iu length ; commlasnro of mouth curved. 



THALKICIITHYS, 791. 



hh. Body very slender, the depth 6 in lengtli ; commissure of mouth nearly straight. 



ATTENUATU6, 792. 

 OSMERITS : 



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. 



(I. Maxillary not reaching posterior margin of eye ; depth (> to 63^ in length ; colora- 

 tion plain. MORDAX, 793. 

 chl. Maxillary reaching posterior margin of eye; depth S'j in length; coloration 

 brilliant. DENTex, 794. 



Subgenus SPIRINCHUS, Jordan A Evermann. 



791. OSJIEKLS THALEICHTHYS, Ayres. 



Head 4A ; 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 iiupil ; 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. 

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



Osmeru.i thaleulithiis, Ayres, Proc. Cal. Ac. Nat. Sci., 1860, 62, San Francisco ; GCnther, Cat., 

 VI, 168, 1866 ; Jordan & Gubert, Synopsis, 292, 1883. 



