150 



Usually confounded with our common gudgeon, wliidh it 

 closely resembles. It seems to be uncommon, but a few 

 specimens have been taken in the fresh-water part of the 

 Patapsco Eiver. 



Acad, Coll. S. I. 



2— H, procne. 



This small species may be readily distinguished by its long 

 caudal peduncle and tail, its large brown-edged dorsal scales, 

 and plumbeous lateral band. The height of the body is 

 about one-titth of the total length (without caudal), the 

 length of the head somewhat less than one-fourth. The fins 

 are unspotted, and a blackish line runs along the lateral 

 line, 



Fin-rays:— D. 1. 8; P, 12— ]3; V. 1, 8; A. 1. T; C, 19. 



Leuciscus proL-ne, Guenther, VII, p. 260. 



Eyhognaflms iiroene, Cope, Proc. Acad, Nat. Sc, Philad.^ 

 1864, p, 283. 



Hyhopsis procne, Co\)e, Journ, Ac. Sc. Philad. XIII, p. 

 385, pi. XI, fig, 2, 



Found in the Upper Potomac and in the Canal, Washing- 

 ton county, by Major J. B. Ferguson. 



Acad. Coll. S, I. 



HYBOGNATHUS, Girard. 



H. regius. 



Minnow, 



Body elongated, compressed, its depth being one-fifth or 

 rather less than one-fifth of the totsl length (without caudal); 

 the length of the head is one-sixth of the total. Coloration 

 uniform. 



Fin-rays:— D, 11; A. 11. 



H. regius, Girard, Proc. Ac. Xat. Sc. Philad. 1856, p. 209, 



Common in the upper parts of the Patapsco River, in the 

 Potomac, and in all the larger creeks of Baltimore county, 

 north and west of the city, 



Acad, Coll. S. I. 



LVI-SILURIDH. 



iELURICHTHYS, Baird & Girard. 



A, marinus. 



Oceanic Cat-Fish, or Fork-Tailed Cat-Fish. 



Body cylindrical, tapering behind ; its greatest depth at 

 the origin of the first dorsal, where it is one^sixth of the 



