146 



PROCEEDINGS OF THE ACADEMY OF 



[1883. 



and a little exceeds the length of the muzzle. The mouth slopes 

 upwards, and the extremity of the maxillary bone reaches to the 

 anterior edge of the orbit. The ventral fin originates behind the 

 point below the first dorsal ray by the width of a ray. TJie fins 

 are all rather small, except the caudal. The sides and belly are 

 a pure silver-white up to the eighth row of scales below the dorsal 

 fin. Above that line the sides and back are a light brown, 

 becoming lead-colored along the border of the white. In some 

 specimens this lead-color forms an obscure band. 



Measurements. 



M. 



Total length with caudal fin, "104 



Length to edge of operele, *021 



Length to first dorsal ray on lateral line, . . -042 



Length to first ventral ray on lateral line, . . '043 



Length to first anal ray on lateral line, . . . '060 



Length to caudal fin on lateral line, . . . '084 



Depth at first dorsal ray, "019 



Depth at first anal ray, ' •0148 



Depth at first caudal peduncle, 009 



Width of interorbital space, .... 'OOt 



Width of orbit, -006 



This species exists in immense numbers in Pyramid Lake, where 

 it doubtless furnishes much food for the trout, Salmo purpuratus. 



LeactiS altarcus Cope. Anchybopsia altarcus Cope, Proceeds. Amer. Philos3ph. Soc, 

 1877, p. 229. 



Extinct; from Fossil Lake, Oregon, only. Represented by 

 pharyngeal bones and teeth. 



SIPHATELES Cope. 



Gen. Nov. Char. — Pharyngeal teeth 5-5, with well developed 

 grinding surfaces. Ventral fins beneath the anterior part of the 

 dorsal. Lateral line very imperfectly developed. 



This genus is Leucus, with undeveloped lateral line. The only 

 species does not resemble any of the others here described. 



Siphateles vittatus sp. hot. 



Scales 11-55-5 ; radii D. I. 8 ; A. I. 8. Head 4 times in length 

 without caudal fin ; depth of body 4*5 times in the same. Eye 

 one-third of length of head, and a very little less than interorbital 



