108. With one row of teeth in each jaw; usually with nine to twelve rays in 



the dorsal fin; scale count 25 to 32 109. 



Teeth in two or more rows; usually with eleven to thirteen rays in the 



dorsal fin; scale count 34 to 39 110. 



109. Depth of body about one-fourth of length; with a dark stripe along each 



side ending in a spot at the base of the tail fin; Florida everglades 

 Chriopeops goodei (Jordan) Florida Killifish 

 (Lucania goodei Jordan) 

 Depth of body about one-third of length; sides and back greenish; with 

 a dark spot at the base of the dorsal fin; Atlantic and Gulf coasts 

 Lucania parva (B. ^ G.) Rainwater Fish, Little Killifish 



110. Fins plain colored; dorsal fin usually with thirteen rays; sides of male 



dark barred; southern West Coast 



Fundidus parvipmms Girard Western Killifish 

 Fins with light or dark spots; dorsal fin usually with eleven or twelve 

 rays; Atlantic and Gulf coasts 111. 



111. Snout short, about equal in length (before eye) to the diameter of the 



eye; fins usually pale spotted; females mostly plain colored; males with 

 silvery bars on sides; Atlantic and Gulf coasts 



Fundidus hetcrochtus (Linn.) Common Killifish, Mummichog 

 Snout longer; fins usually dark blotched; with dark bars (males) or dark 

 stripes; Atlantic coast 



Fuyidulus viajahs (Walbaum) Mayfish 



112. Scale count about 30 to 60; with 18 to 25 rays in the pectoral fins; sides 



dark barred, faintly dark striped in the breeding season; northwestern 

 U. S.; Family T^ovumhridae 



T^ovumhra hubbsi Schultz; Western Mud-minnow 

 Scale count about 30 to 40; with about 14 rays in the pectoral fins; sides 

 dark barred or dark striped; eastern and central states; Family Uw 

 hridae 113. 



113. With transverse bars; northeastern and north-central states 



Umbra limi (Kirtland) Eastern Barred Mud-minnow 

 With lengthwise stripes; Atlantic slope 



Umbra pygmaea (De Kay) Eastern or Striped Mud-minnow 



114. Gill membranes (thin wall of skin closing the gill chamber below) free 



from the isthmus (fleshy part between the gill openings), so that they 



appear split far forvv'ard and meeting at an acute angle below the chin; 



jaw teeth may or may not be present 115. 



Gill membranes broadly joined to the isthmus; no teeth on the jaws 121. 



115. Lateral line present; Family Hiodontidae 116. 

 No lateral line 117. 



116. With nine rays in the dorsal fin; Ohio Valley and Great Lakes 



Amphiodon alosoides Raf. Goldeyes 

 With twelve rays in the dorsal fin; Mississippi Valley 



Hiodon tergisus LeSueur Mooneye, Silver Bass 



117. Last ray of dorsal fin much elongated; eastern and central states; Family 



Dorosomidae 



271 



