2824 Bulletin 4.7, U?iited States National Museum. 



Scales small, deciduous, those on back still smaller; lateral line distinct. 

 Gill rakers long and slender, about 12 below angle of arch, longest about 

 as long as eye. Tongue with moderate teeth, the anterior 2 to 4 small 

 hooked canines; upper jaw with small sharp teeth similar to those in 

 lower jaw, none of them canine-like; small teeth on palatines and ptery- 

 goids; vomer with 2 very small canines scarcely fang-like. Color blu- 

 ish above with bright reflections ; scales margined with dark points ; sides 

 silvery with golden and coppery luster; inside of gill openings dusky; 

 tins white, somewhat dotted. About Kadiak Island, Alaska. Two speci- 

 mens caught in the upward haul of a dredge in Shelikof Straits, north of 

 Karluk, Kadiak Island, Alaska, at Albatross Station No. 3675. The depth 

 of the dredge haul was 109 fathoms, but these fishes were no doubt taken 

 from near the surface. One specimen is 8, the other about 7 inches in 

 length. The species is allied to Osmerus dentex, the Rainbow Smelt, but 

 differs in the extremely long anal and in the very weak vomerine and 

 lingual canines. The flesh is firm, as in 0. dentex. (Named for the 

 U. S. Fish Commission steamer Albatross.) 



Osmerus albatrossis, JORDAN & GILBERT, Kept. Fur. Seal Invest., MS. 1898, Shelikof 

 Straits, north of Karluk, Alaska. 



Mesopus should replace Hypomesus. It is originally characterized on 

 page 14 (not 168) Proc. Ac. Nat. Sci. Phila. 1862, Hypomesus on page 15. 

 The ventrals are inserted below front of dorsal in Mesoptis as in allied 

 genera, and there are 8 branchiostegals as in allied groups. The feeble 

 teeth distinguish Mesopus from Osmerus. The statement that the stomach 

 is csecal in Argentinidce is true of a few genera only, and the character has 

 no high systematic value. In Mesopus pretiosus and Osmerus dentex, the 

 stomach is siphonal, as in Salmonidce. In Thalriohthys pacificus, however, 

 the stomach forms a blind sac. The small number of pyloric caeca and 

 the peculiar structure of the ovaries remain to define Argentinidce as a 

 family distinct from Salmonidte. 



Page 525. To the synonymy of Hypomesus olidus add: 



Osmerus oligodon, KNER. 



The species ranges south to Amur River. 



Page 530. After BatUylag us pacificus add: 



804(a). BATHYLAGUS BOREALIS, Gilbert. 



Head 4^ to base of caudal ; depth 5f ; eye 2 in head ; snout 2f in eye. 

 D. 8; A. 19; ventral 8 ; pectoral 8. Scales in about 40 rows, judging from 

 the scars ; head scaleless. Interorbital width grooved, the groove widen- 

 ing posteriorly, opening onto the flat occipital region, which is not 

 swollen. Width of cartilaginous portion of interorbital space ^ orbit; 

 including the thin rueinbranaceous plates which overarch the orbits, the 

 interorbital width is orbit. The anterior profile of snout declines gently, 

 bringing the mesial portion of premaxillaries on a level with lower margin 

 of pupil. Distance from tip of snout to end of maxillaiy slightly exceed- 

 ing length of snout, 2i in orbit. Opercle with 2 strong ridges diverging 

 downward and backward from behind the eye. Front of dorsal midway 



