68 



PROCEEDINGS OF UNITED STATES NATIONAL MUSE DM. 



The whole fish is highly transparent when fresh, the outline of the 

 brain being clearly visible through the occiput. 



From Osmeriis thaleichthys, which at first sight nearly res;embles it, 

 this species may be distinguished by the following characters: The 

 slightly greater length and more tapering form of the snout, when 

 viewed from above; the straight lower jaw, which in 0. thaleichthys is 

 considerably curved upwards toward the tip ; the gradual declivity of 

 the upper outline of the head, which in the latter species is straight 

 with the line of the back 5 the larger eyes; the different arrangement of 

 the teeth ; the more elongated body, much less curvate along the abdom- 

 inal outline ; and the much greater distance between the tips of the 

 pectorals and the base of the ventrals. 



Dimensions. 



No. 1. 



No. 2. 



No. 3. 



No. 4. 



No. 5. 



No. 6. 



Total lenjrth 



Greatest depth of body 



Length of head, to tip'of lo-wer jaw .. 



Longitudinal diameter of eye 



Interorbital width . . 



Length of snout, to tip of upper jaw . 



Length without caudal 



Tip "of lower jaw, to adipose fin 



Tip of lower jaw, to ventrals 



Length of pectoral 



Height of dorsal 



Length of ventral 



Tip of li)wor jaw to origin of dorsal. . 



Lencth of lower jaw 



Width of caudal peduncle 



Inches. 



4.12 



.55 



.96 



.23 



.19 



.23 



3.47 



2.97 



1.97 



.50 



.45 



2.00 



.56 



.20 



Inches. 



4.50 



.58 



1.00 



.23 



.20 



.25 



3.84 



3.00 



2.10 



.58 



.56 



.45 



2.15 



.60 



.20 



Inches. 



5.25 



.60 



1.13 



.30 



.23 



.28 



4.42 



3.62 



2.56 



.63 



.61 



.56 



2.56 



.68 



.24 



Inches. 



5.72 



.72 



1.25 



.29 



.31 



.30 



4.87 



4.14 



2.68 



.72 



.75 



.64 



2.75 



.70 



.30 



Inches. 



5.06 



.62 



L12 



.25 



.26 



.28 



4.30 



3.60 



2.35 



.05 



.02 



.53 



2.40 



.60 



.26 



Inches. 



6.00 

 .75 



1.32 

 .cO 

 .•i45 



.al 



5. (.9 



4.31 



2.76 



.81 



.69 



.69 



2.94 



.31 



Nos. 1, 2, and 3 are alcoholic specimens ; the others were measured while fresh. 



The comparatively elongate form of this fish induced me to believe 

 that this species must be 0. elongatus Ayres (Proc. Cal. Acad. Sci., I, 

 17, 1854), but as the latter ichthyologist transmitted examples of his 

 species to Washington, and these examples were examined by Girard, 

 and found by him to be identical with his Osmerus pretiosiis (= Argen- 

 tina pretiosa Grd. = Hgpomesus oUdtus (Pallas) Gill), there is no doubt 

 that the foregoing is an undescribed species. 



There are thus four species of Microstomatidce on the Pacific coast, 

 United States, viz, Thaleichthys pacijicus, Kypomesus olictus, Osmerus 

 thaleichthys, and 0. attenuatus. The first of these does not occur in the 

 markets of San Francisco, but is sent down packed in salt from the 

 Columbia Eiver, also to some extent in oil, under the name of " Colum- 

 bia River sardines." The other three are brought into the markets in 

 a fresh state. Hypomesus olictus grows to the largest size, and is most 

 highly esteemed of the three. Osmerus attenuatus is tolerably abundant 

 iu the markets during the spring and summer months. 



