104 FISHES OF ILLINOIS 



kk. Lower portion of head with an appearance of being swollen, the suborbitals, 

 interopercles, and dentaries with greatly distended mucus cavities, ap- 

 pearing externally as transverse vitreous streaks; teeth 4-4 or 1, 4-4,1. 



Ericymba. 



jj. Lower lip with two lateral fleshy lobes, separated at the middle by the more 

 or less horny and knob-like chin; scales rather small, 40 to 60 in lateral line; 

 teeth 4-4 Phenacobius. 



ee. Maxillary with a barbel* at or near its extremity (sometimes quite small and 

 difficult to make out, especially in preserved specimens). 



1. Barbel on upper side of maxillary and distinctly in front of its posterior tip; 

 mouth exceptionally large, maxillary 2.4 to 2.8 in head; scales 50 to 60; 

 teeth 4 or 5 in main row, 1, 2, or in lesser row Semotilus. 



II. Barbel terminal on the maxillary, situated in the axil formed at meeting of 

 upper and lower lip-grooves; maxillary more than 2.8 in head. 



m. Premaxillaries not protractile; scales small, 60 to 70; dorsal fin posterior; 

 teeth 2, 4-4, 2 Rhinichthys. 



mm. Premaxillaries protractile. 



n. Scales 35 to 45 in lateral line; teeth 4-4, or 1, 4-4, 1 or Hybopsis. 



nn. Scales small, 50 to 60 in lateral line; head much depressed and flattened 

 above; teeth usually 2, 4-4, 2 Platygobio. 



Genus CYPRINUS (Artedi) Linn.^us 

 (the carp) 



Mouth with four long barbels; teeth molar, broad and truncate, 1,1, 

 3-3, 1, 1; dorsal fin very long, with a stout spine which is serrated be- 

 hind; anal fin with a seiTated spine. Native to fresh waters of Asia; in- 

 troduced into ponds and streams of both Europe and America, where 

 they are now abundant. 



CYPRINUS CARPIO Linn^us 



(GERMAN carp) 



Linnseus, 1758, Syst. Xat., Ed. X, 320. 



G., VIL 25; J. &G., 254; M. V., 50; J. & E., I, 201; L., 13. 



Length 2 feet or over; body robust, compressed; back considerably 

 elevated ; general form resembling that of the buffalo-fishes (Ictiobus) ; 

 depth in length 2.75 to 3.4 (as a rule less than 3) ; depth caudal peduncle 

 1.2 to 1.4 in its length. Color olivaceous, upper parts dusky to bluish; 

 lower part of sides and belly more or less yellowish. Head conical, 

 tapering rapidly from above to the tip of the pointed snout, 3 to 

 4 in length; width of head 1.4 to 1.6 in its length; interorbital space 

 nearly flat, 2.3 to 2.7 in head; eye 5.5 to 6.8 in head; nose bluntly 

 pointed, 2.6 to 3.3 in head; mouth rather small, anterior, oblique, the 

 maxillary not reaching past anterior nostril, 3.3 to 3.9 (usually about 3.5) 

 in head ; two pairs of maxillary barbels, the upper shorter, the lower longer 

 than eye; teeth broad and truncate with molar surfaces, in three rows, 



* Read 1 and 11 for exact indication of location of barbel. 



