CATFISH GENUS NOTURUS RAFINESQUE 211 



Description. — Comparison of the hybrids with specimens of 

 Noturus gyrinus and Noturus miurus is given in table 15. A fifth hybrid 

 of this combination, from the western end of Lake Erie, was described 

 by Trautman (1948). In the hybrids examined, body moderately 

 short, little deeper forward than through caudal peduncle, deepest 

 below dorsal spine; head broad, generally flat above, rather deep; skull 

 somewhat arched; upper jaw usually slightly longest; lower jaw ending 

 at about middle of upper lip in three specimens; jaws virtually equal 

 in Indiana specimen; barbels rather short; posterior process of clei- 

 thrum prominent, a little longer than maximum diameter of pectoral 

 spine; pectoral spine (pi. 3, fig. 12) slightly curved, without anterior 

 serrae, prominent deep grooves present only in small specimens; 

 posterior serrations present, but short and irregularly spaced or fused ; 

 dorsal spine stout; adipose fin broadly connected to the rather high 

 upper procurrent caudal fin, with a very shallow indentation at junc- 

 tion; caudal fin almost truncate behind, with a rounded posterior 

 margin; premaxillary tooth patch rather broad, the width of the band 

 about 4 times its length; posterior corners of the band rounded. 



Additional data are given in sequence for the specimens as follows: 

 UMMZ 157214, UMMZ 167302, CU 42514, and USNM 199583. 

 Standard length (in mm.) and sex: 108.8, probably female; 67.9, 

 female with large eggs; 55.0, sex omitted; 33.0, sex uncertain. Anal 

 rays: 17, 15, 15, 15. Upper branched caudal rays: 21, 17, 17, 7. Lower 

 branched caudal rays: 13, 14, 13, 10. All have six soft dorsal rays. 



The following stepped measurements of the two Michigan specimens 

 and the New York specimen fall within the range obtained from 

 Michigan N. gyrinus and A'', miurus: Head length in standard length 

 3.2 to 3.45 times; predorsal length in distance dorsal fin origin to 

 adipose notch 1.3 to 1.4; distance from adipose notch to tip of caudal 

 fin in distance dorsal fin origin to adipose notch 1.2 to 1.5. In two 

 specimens, the length of the dorsal spine in the predorsal length 

 (2.6 to 2.65) and the length of the pectoral spines in the predorsal 

 length (2.1 to 2.3) fall within the range obtained from Michigan 

 A'', miurus, but not Michigan N. gyrinus; these measurements do, 

 however, fall within the range obtained for all specimens of N. gyrinus 

 measured. In the three specimens, the caudal peduncle shows inter- 

 mediacy, its depth in the predorsal length (2.7 to 2.75) overlaps 

 slightly the same measurement obtained from Michigan N. gyrinus 

 but is outside the range obtained for all specimens of N. miurus 

 measured. 



In the largest specimen there are 35 vertebrae. Its pectoral and 

 dorsal spines are broken. There are no anterior serrae, but the posterior 

 serrae of the pectoral spine are extremely irregular (pi. 3, fig. 12). 

 The eye is stepped 2.6 times in the snout, and there are nine gill 



