Jorda7i and ETermann. — Fishes of North America, 213 



DioNDA (a coined namo) : 

 aa. Tooth coinparativoly short, distinctly hooked ; suhorbitals moderate ; phimbeous species, 

 usually with dark lateral band, the adult less than 3 inches long. 

 d. Scales in lateral lino 32 to 43. 



«. Body rather slender, the depth 4 to 4J^ in length. 



/. Scales largo, 32 to 34 in lateral lino. Serena, 343. 



Sf. Scales smaller, usually 37 to 40 in the lateral line. 



g. Sides with a dark lateral band, ending in a more or less distinct dark spot 



at base of caudal. 



/(. Cleft of mouth about Ti in head ; snout bluntish. episcopa, 344. 



hh. Cleft of mouth al)out 4 in head, tho snout more acute. nubila, 345. 



gg. Sides without distinct dark lateral band ur caudal spot ; body elliptical in 



outline ; eye 3' fj in head, rather longer than snout. amara, 346. 



ee.. Body rather stout, the dejith "A^i to 3% in length ; scales about 37 ; sides with 



dusky band and caudal spot. melanops, 347. 



i/i/. Scales in lateral lino 50 to GO ; body rather slender, the depth ^y'^ in length. 



PLUMBEA, 348. 



Subgenus HYBOGNATHUS. 



340. HYBOGXATHUS NUCHALIS, Agassiz. 



(Silvery Minnow.) 



Head 4| to 5; depth 4i; eye 4, D.8; A. 7. Teeth 4-4; scales 5-38-4. 

 Body elongate, comparatively slender. Head moderate, rather short, the 

 profile evenly curved ; suborbitals broad, the anterior about twice as long 

 as deep. Eye moderate, rather longer than muzzle. Upper jaw heavy ; 

 lower jaw thin. Scales large and silvery. Lateral line decurved ; 12 to 

 14 largo scales in front of dorsal. Intestines very long, 7 to 10 times 

 length of body. Olivaceous green above, translucent in life ; sides clear 

 silvery, with bright reflections ; fins unspotted, coloration becoming 

 dusky ill specimens living in dark waters. Length 4 to 7 inches. A 

 graceful minnow, abundant in clear streams from the Delaware and Neuse 

 to the Upper Missouri and southward to Georgia and Texas; common in 

 or near large rivers. Variable; tangible varieties are : subspecies 2>?((ci<rt, 

 (Girard),from the Arkansas and Missouri rivers, the eye smaller, 5 in 

 head; tho snout depressed and blunt, with very small mouth ; subspecies 

 regia, (Girard), Potomac Eiver, more than 6 inches long (western forms 

 are usually less), with deeper body and larger eye, 3f in head; the form 

 called osmcrhtiis, from Delaware River, is not evidently different from 

 nuchaUs, which is tlie common form of the Missouri Valley, {nuchalis, 

 pertaining to the naiie.) 



Hi/bognalhiis nnchalis, AoASSiz, Amor. Journ. Sci. Arts, 1855, 224, Quincy, Illinois. (Coll. Dr. 



Watson.) OrNTHEK, Cat., vii, 184, ISfiS ; Jordan & Gilbert, Synopsis, 150, 1883. 

 ITyhogniilliitu jtlnri/ux, OiitARn, I'roc. Ac. Nat. Sci. Phila., 185G, 182, sluices of the Arkansas 



River, Fort Makee, Arkansas. (Typo, No. 87. Coll. Dr. Suckley.) 

 Hybognathus eimixi, Girard, Proc. Ac. Nat. Sci. Phila., 185C, 182, Fort Pierre, Nebraska. 



(Coll. Dr. Evans.) 

 Hyhognathiis regiiis, Girard, Proc. Ac. Nat. Sii. Phila., 1856, 209, Potomac River. (Coll. 



Girard.) Gi'NTiiER, Cat., vii, 185, 1868. 

 Bybognathus osmerinus, Cope, Proc. Amor. Phil. Soc. Phila., 1870, 466, Raritan River, New 



Jersey. (Coll. C. C. Abbott.) 



