64 VERTEBRATE ANIMALS OF THE UNITED STATES 



hi Teeth i -rowed, being 4-4. 



ii Scales about 38 in the lateral line. 



ji Scales without a keel 44. Extrarius. 



}2 Scales with a keel 45. Macrhybopsis. 



\i Scales 44 to 50 in the lateral line. . . .46. Erimystax. 



ho Teeth 2-rowed, being 2, 4-4, 2 or i 47. Erinemiis. 



g2 Size large, being 250 mm. or more in length. 



hi Head large and broad 48. Nocomis. 



h.1 Head small, very broad, depressed 50. Platygobio. 



do Lower jaw 3-lobed; eastern States 51. Exoglossum. 



I. Cyprinus L. Body robust, compressed; mouth with 4 long 

 barbels; snout rounded; pharyngeal teeth i, i, 3-3, i, i; scales large; 

 dorsal fin very long; anal short: i species. 



C. carpio. L. European carp (Fig. 31). Length 450 mm. or more; 

 head 3 to 4; depth 2.75 to 3.4; color blackish gray above, yellowish on 

 the sides and belly; 3 spinous and 17 to 21 soft rays in dorsal fin and 3 



Fig. 31. — Cyprinus carpio {from Siissw. Fauna Dent.). 



spinous and 5 soft rays in the anal fin; scales 5 or 6-35 to 37-5 or 6: 

 fresh waters of eastern Asia and introduced into Europe and America; 

 abundant and an important food fish in the eastern and central parts of 

 the country. 



2. Carassius Nilsson. Body oblong; mouth without barbels; scales 

 large; pharyngeal teeth 4-4; dorsal fin very long: i species. 



C. auratus (L.) Goldfish. Length up to 400 mm. ; color olivaceous, 

 becoming reddish or golden in domestication, but often reverting to the 

 natural color, when wild; 2 spinous and 18 soft rays in the dorsal and 2 

 spinous and 7 soft rays in the anal fin: Asia and Europe, first domesti- 

 cated in China; in many ponds and streams in the eastern States. 



3. Campostoma Agassiz. Body elongate; teeth with an obHque 

 grinding surface and a shght hook; air bladder surrounded by numerous 

 convolutions of the very long alimentary canal, an anatomical feature 

 found only in this genus of fishes: 4 species, i in Mexico. 



