SILURID^E. CX. 335 



much mottled; anal fin quite short, of 15 rays. A sin- 

 gular species, reaching a very large size, abounding on 

 the bottoms of our larger Western and Southern rivers. 



4. NOTURUS, Rafinesque. STONE CATS. 



* Intermaxillary band of teeth with strong lateral backward pro- 

 cesses, as in Pelodichthys. (Noturus.) 



1. H. flavus, Raf. YELLOW STONE CAT. Head much 

 depressed and flattened, little longer than broad; bar- 

 bels rather short; head 4^ in length; depth 5f ; distance 

 from snout to dorsal 3; middle of body cylindrical, some- 

 what carinate above; adipose fin notched; spine of pec- 

 torals roughish behind, slightly retrorse-serrate in front. 

 St. Lawrence to Kentucky and Upper Missouri, abund- 

 ant, the largest species, reaching a length of a foot. 



** Intermaxillary band of teeth without lateral backward pro- 

 cess. (Schilbeodes, Bleeker.) 



t Pectoral spines more or less serrate on the inner edge ; adi- 

 pose fin notched. 



a. Pectoral spines rather small, their internal serrae feeble, less 

 than halt' the diameter of the spine; anal rather long, of 

 more than 14 rays. 



2. N. insignis, (Rich.) Gill & Jor. MARGINED STONE 

 CAT. Upper jaw decidedly longest; pectoral spine about 

 half length of head, pretty strongly retrorse - serrate 

 externally, dorsal spine much nearer anal than snout, the 

 distance from snout to dorsal more than one-third the 

 length; anal fin with 16 to 19 rays; body elongate; 

 head flattened; dusky, a distinct black margin to dorsal 

 and caudal fins; size rather large; Pennsylvania to S. 

 Carolina, abundant. [JV. lemniscatus, (Val.) Grd. N~. 

 in <i i -<j ii i a t us, B ai rd .] 



3. H. exilis, Nelson. SLEXDER STONE CAT. A sort 

 of "starved" representative of the preceding, smaller 



