168 SALMONID^, 



the number of transverse series above the lateral line being 66. The 

 posterior mandibular)* teeth not larger than the anterior ones. 



Atlantic side of the United States. 

 a. Fine specimen, 10 inches long. Boston, Presented by B. Win- 

 stone, Esq. 

 6. Half-grown. New York, Purchased of Mr. Brandt. 

 e. Adult, in bad state. Presented by the Smithsonian Institution. 



3. Osmerus thaleichthys. 

 Ayres, Proc. Calif. Acad. Nat. Sc. 1860, p. 62, fig. 12. 

 B.8. D.9. A. 19. P. 11. Y.8. 



The length of the head is one-fourth of the total (without caudal), 

 the height of the body one-fifth ; the diameter of the eye is one-fourth 

 of the length of the head. The maxillary reaches to the vertical 

 from the hind margin of the eye. Teeth on the tongue largest. The 

 origin of the dorsal fin is a little nearer to the root of the caudal than 

 to the extremity of the snout ; ventral fins entirely in advance of the 

 dorsal. (Ayres.) 



Common in the Bay of San Francisco. 



7. THALEICHTHYS. 

 Thaleichthys, Girard, U. S. Pac. R. R. Exp. Ihh. p. 325. 



Body covered with small scales. Cleft of the mouth wide ; max- 

 illary long, narrowish, extending nearly to b6low the hind margin of 

 the eye ; lower jaw prominent. Dentition rudimentary*, only a few 

 minute teeth being visible on the maxillary and intermaxillary; 

 mandible, tongue, and palate apparently toothless. Pectoral fins 

 moderately developed ; anal long ; caudal deeply forked. Pseudo- 

 branchiae present, but rudimentary. Stomach with a rather long 

 blind sac ; pyloric appendages slender, in moderate number. Testes 

 double ; ova very small. 



Pacific coasts of North America. 



1. Thaleichthys pacificus. 



The Eulachon, Oulachkn. 



Salmo (Mallotiis ?) pacificus, Richards. Faun. £or.-At)ier. iii, p. 226. 



Thaleicnthys stevensi, Girard, U. S. Pac. R. R. Exp. Fish. p. 325, 



pl.75(76). figs. 1-4. 

 pacificus, Girard, Proc. Acad. Nat. Sc. Philad. 1858, p. 225; 



Cooper 8)- Suckley, Nat. Hist. Washingt. Terr. p. 348. 



B. 8. D. 11-12. A. 21. P. 11. V. 8. L.lat.78. C. pyl. 11. 



Yert. 70. 

 The height of the body is much less than the length of the head, 

 which is contained four times and one-third in the total (without 

 ^audal). Snout much longer than the diameter of the eye, which is 



• The teeth kre so minute that bones which are described as tooth-bearing in 

 one specimen may be toothless in another. 



