62 



cxten(lin!2; the entire len";th of the fish ; all below the lower ones 

 of these lines of a bright silvery satin lustre. 



This species is apparently quite rare, as but a "Single specimen 

 has been obtained, which was found in the market in San Francisco. 

 It is six inches in len2:th. 



Osynerus thaleicJithi/s, (Ay res) Fig. 12. — Form elongated, 

 compressed ; head forming about one-fifth the total length ; great- 

 est depth one-sixth of the length ; depth at the origin of the 

 caudal fin a little more than one third of the greatest depth ; eyes " 

 large, distant about their own diameter from the lip of the upper 

 jaw, forming one-fourth of the length of the head. 



Gape of the mouth wide, the tips of the maxillary reaching a 

 line nearly even with the posterior border of the orbit ; teeth sharp, 

 distinct, separate, in the lower jaw, and on the maxillary, premaxil- 

 lary, vomer, palatine and pterygoid bones, and on the tongue. 

 Those on the tongue are largest ; those on the palatine bones are 

 not numerous, and are chiefly on the anterior portion. 



Operculum angular posteriorly, the curve continued by the sub- 

 operculnra ; branchial apertures wide ; branchial rays, eight. 



Scales rather large, soft ; those of the back and upper part of 

 the sides renil,ered somewhat conspicuous by a bordering of brown 

 points which form decussating lines ; lateral lines at first curving 

 downward, and then running nearly straight to the caudal fin. 



The first dorsal fin arises a Uttle in advance of the middle of the 

 length of the fish ; it is quadrangular, its height anteriorly about 

 equal to the depth of the fish ; its length half its height ; the height 

 of the last rays one third of the height anteriorly. 



The adipose fin is distant from the termination of the first dorsal 

 by a space equal to the length of the head ; it is nearly as high as 

 the last j-ays of the first dorsal. 



The anal fin, extending a little further backward than the line of 

 the adipose fin, is equal in length to the de])th of the body ; its 

 greatest height, at the fifth ray, is half the length of the head. 



The ventral fins, situated in advance of the line of the first dor- 

 sal, are rounded, as high as the depth of the body. 



The pectorals are rounded, as high as the length of the head, 

 extending beyond the insertion of the ventrals. 



The caudal fin is somewhat concave on its margin ; the height of 

 the external lays equal to that of the ventrals. 



D. 9 ; A. 19, P. 11, V. 8, C. 9. 1. 9. 8. 1. 10. 



Color, greenish olive above, sprinkled with minute dark points ; 

 silvery on the sides and beneath. 



This species is quite common in the bay of San Francisco, being 

 Iroudit in numbers into the market, and sold iudiscriminatelv with 



