50 



VERTEBRATE ANIMALS OF THE UNITED STATES 



Family 6. Argentinidae.^Smelt. Body elongate, slender, small, 

 covered with usually cycloid scales; head naked; mouth terminal; 

 stomach a blind sac, the cardiac and pyloric ends being close together; 

 pyloric caeca few or wanting; adipose fin present; tail forked: about 12 

 genera and 15 species, mostly marine, some of the species ascending the 

 streams; 2 genera in the United States. 



I. Thaleichthys Girard. Body very slender; scales very small; 

 teeth very feeble: i species. 



T. pacijicus (Richardson). Candlefish. Length 300 mm.; head 

 4.75; depth 6; color white, with numerous dark dots above; rays of 

 dorsal fin 11; anal 21; scales 75; lower jaw projecting: Oregon to 



Fig. 24. — Thymallus tricolor {from Jordan i^ Evermann) . 



Alaska; marine; ascending the streams from the Fraser River north- 

 wards in enormous numbers in the spring; flesh very oily and of delicious 

 flavor; an important food fish; when dried used as candles. 



2. Osmerus L. Body very slender; teeth strong, those on the 

 tongue long and fang-like; scales large; 5 species in the United States 

 along the shores of both oceans, i ascending the streams. 



O. mordax (Mitchill). American smelt. Length 300 mm.; head 4; 

 depth 6.5; color greenish above, with dark dots; sides silvery; rays of 

 dorsal fin 10; anal 15; scales 68; mouth large, lower jaw projecting: 

 Atlantic Ocean from Virginia to Labrador, ascending the streams in the 

 winter to spawn in immense numbers; common in Lake Champlain and 

 other lakes; often landlocked; an important food fish. 



O. thaleichthys Ayres. Length 200 mm.; head 4.5; depth 5.5; color 

 olivaceous; rays of dorsal fin 9; anal 14; scales 55 to 58: Pacific Ocean 

 from San Francisco to Alaska, ascending the streams in February. 



Order 2. Apodes. — Body very elongate, cylindrical, with minute 

 imbedded scales or none; ventral fins wanting; anterior vertebras dis- 

 tinct, without Weberian ossicles; premaxillaries atrophied or absent; 



