44 FISHES OF THE VICINITY OF NEW YORK 



a4. A large black spot on the upper posterior 

 part of the back fin. Silverfin 



b4. No black on back fin. 



a5. Lateral line extending back only a short 

 distance. A bold black stripe from snout to 

 base of tail. Bridled Minnow 



b5. Lateral line extending to base of tail. Length- 

 wise stripe less black and bold. 



Delaware Minnow 



b2. Two teeth in second row. 



a3. Scales about 33, a black stripe on sides. 



Abbott's Minnow 



b3. Scales smaller, 37-43. 



a4. Scales, especially on shoulders, very deep and 

 narrow Redfin 



b4. Scales not especially narrowed. Color trans- 

 lucent greenish. Raritan Minnow 



Of the species in this Key, the Blunt-nosed Minnow, Rosy Dace, 

 Gold-thread Shiner, Delaware, Abbott's and Raritan Minnows and 

 Horny-head are rare in this vicinity and their status not well known. 

 The Fallfish is uncommon, the Silvery Minnow tolerably common, the 

 Bridled Minnow, Silverfin and Delaware Minnow are locally common, 

 the Redfin generally common. Of the last five all are small species 

 except the Redfin, which reaches a length of eight inches. Large speci- 

 mens of the Redfin have the shoulder region much expanded. Spring 

 males have the lower fins rosy, the region from back fin to snout and 

 lower jaw covered with small tubercles. 



IV. Herring, Trout, etc. 

 (Isospondyli) 



Herring-like fishes like the carps have a single central back fin of 

 soft jointed rays. The mouth varies in si^ce with small teeth or none, 

 and they do not have the comb-like pharyngeal teeth so characteristic 

 of the latter. The species characteristically inhabit salt water, though 

 many of them enter brackish or even fresh water. They are fishes of 

 delicate texture which die quickly out of water. 



The Tarpon is a gigantic herring-like fish with protruding lower 

 jaw and the last ray of the back fin elongated in a filament. It commonly 

 enters the mouths of semi-tropical rivers where it is much sought after 



