i68 Natural History Bulletin. 



The species seldom attains a length of twelve inches, and 

 is too small to be of economic importance. 



jj Pre-maxillarj band of teeth without backward lateral processes. 



k Pectoral spine retrorse-serrate in front, with about 6 small teeth behind. 

 Anal rajs 14 to 17. 



17. Noturus exilis. — Nehon. 



This species seldom reaches a length of 4 or 5 inches, 

 Scarce and of no value. Wisconsin, low^a and Kansas. 



kh Pectoral spine entire, grooved behind. Adipose fin continuous with the 

 caudal. One or more narrow black lateral streaks. Anal rays 15 or 16. 



18. Noturus gyrinus. — Mitchill. 



More common in this state than the two preceding species. 

 Length about 5 inches. Hudson river to Minnesota, Iowa 

 and south. 



T)F) Body covered with scales, or nearly so. 



"P Ventral fins, if present, abdominal. 



■p Scales cycloid. Dorsal and anal fins without spines. 



C^ Head without scales. Mouth toothless. Gill membranes united to 



the isthmus (the narrow part of the body between the gill mem- 

 branes). 



TI Pharyngeal bones (bones behind the gills at anterior end of the oesoph- 



agus) falciform, and armed with numerous teeth in one row. Dor- 

 sal rays more than 10. 



Family 7. CATOSTOMIDiE.— The Suckers. 



/ Dorsal fin elongate, its rays more than 25. Air bladder in two parts. 



m Body oblong-ovate, its depth yi io % the length of the body (length meas- 

 ured from tip of the snout to the b::se of the caudal fin). 



Genus 12. Ictiobus. — Rafinesque. — The Buffalo Fishes. 



The species of the Buffalo fishes have never been well 

 defined. I have examined a large number in the Muscatine 

 market and recognize the following species: 



n Mouth large, terminal and protractile forwards. The lips thin and scarcely 

 plicate (sucker like). 



