34 U.S. NATIONAL MUSEUM BULLETIN 2 82 



Key to the Species of the Subgenus Schilbeodes 



1. Mouth terminal, jaws about equal; typically 10 preoperculomandibular pores, 



but 11 in some populations of Noturus gyrinus 2 



Mouth inferior, lower jaw included; preoperculomandibular pores normally 

 11, but 10 in some populations, especially Noturus noclurnus 4 



2. Infraorbital and supraorbital canals typically joined anteriorly (1 internasal 



pore); head length in standard length 3.6 to 4.4 times; anal rays 16 to 22; 



vertebrae 36 to 41 3 



Infraorbital and supraorbital canals typically separated anteriorly (2 inter- 

 nasal pores) ; head length in standard length 3.0 to 3.8 times; anal rays 12 to 

 18; vertebrae 32 to 37; pectoral spine lacking serrae . . Noturus gyrinus 



3. Pectoral spine lacking serrae; fins nearly unicolor; caudal rays 56 to 61; 



distance from rear end of adipose fin to tip of caudal fin stepped 1.2 to 

 1.6 times in distance from origin of dorsal fin to rear end of adipose 



fin Noturus lachneri, new species 



Pectoral spine with prominent, well-developed serrae; fin margins often 

 black; caudal rays 44 to 57, usually 47 to 54; distance from rear end of 

 adipose fin to tip of caudal fin stepped 1.6 to 2.5 times in distance from 

 origin of dorsal fin to rear end of adipose fin Noturus exilis 



4. Pelvic rays normally 8; pectoral spine nearly smooth behind; body and fins 



often with numerous clusters of darker chromatophores or freckles. 



Noturus leptacanthus 



Pelvic rays normally 9 or more; pectoral spine nearly smooth, rough, or 



serrate behind; no prominent clusters of chromatophores scattered over 



body and fins 5 



5. Entire abdomen and lower surface of head usually well pigmented, covered 



with large, discrete chromatophores; anal base long, with 18 or more, 

 usually 20 or more rays, and separated from caudal fin by only a narrow 

 space; dorsal spine slender and flexible in young and juveniles, becoming 



stout with age 6 



Abdomen and lower surface of head mostly unpigmented, but pigment often 

 on chin and in a narrow cross band anterior to pelvic fins (very large or 

 old specimens, typically above 80 mm. standard length, often with a diffuse, 

 dark pigment covering the lower surface) ; anal base shorter, of 21 or fewer 

 rays; dorsal spine stout, stiff at all sizes 7 



6. Several prominent, distinct, sharp serrae along posterior edge of pectoral 



spine; anal rays 18 to 25, usually 20 to 22; soft pectoral rays typically 8 



or 9 Noturus phaeus, new species 



Pectoral spine without distinct serrae, or occasionally with one to three 

 irregular size serrae in young, the posterior edge usually only roughened; 

 anal rays 20 to 27, usually 21 to 24; soft pectoral rays typically 9. 



Noturus funebris 



7. Vertical fins with broad light borders; abdomen and lower surface of head 



immaculate; caudal rays 46 to 54; upper-half caudal rays 22 to 27; spines 



very short Noturus gilberti 



Vertical fins dark or dusky, or occasionally with very narrow light margins; 

 chin and area in front of pelvic fins usually with pigment; caudal rays 

 54 to 67, typically 56 or more; upper-half caudal rays 27 to 35, usually 29 

 or more 8 



8. Pectoral spine with discrete serrae which often become irregular or reduced 



in size with age; vertical fins frequently with jet black margins; preoper- 



