FAMILY CYPRINID^ HYDRARGIRA. 219 



Length, 4-0. Depth, 0-3. 



Fin rays, D. 10 ; P. 17 ; V. 6 ; A. 10 ; C. 19 |. 



To this, and various other allied species, is applied the indian name of Mummachog. Like 

 its congeners, it is found in the salt-water creeks about New-York. Dr. Holbrook informs 

 me that it is common in the brackish streams of Carolina. 



GENUS HYDRARGIRA. Lacepede, Lcsueur. 



Head flat, shielded above by large scales ; the central scale largest. Teeth in the jaws and 

 throat ; those in the jaws conic. Scales on the opercles. Branchial rays four to five. 



Obs. M. Lesueur has attempted to renovate a defective genus proposed by Lacepede, but 

 it does not appear to be well elaborated, and has not been adopted by modern ichthyologists. 

 When better studied, it may serve to embrace numerous small fresh-water Cyprinida;, which 

 are not yet well established in the systems. 



THE TRANSPARENT MINNOW. 



HyDRARGIRA DlArHANA. 



Hydrargira diaphana. Lksueue, Journ. Ac, Sc. Vol. 1, p. 130. 



Characteristics. Body diaphanous, with sixteen transverse brown bands, confluent above. 

 Dorsal fin double the size of the anal. Length 3-5 inches. 



Descriptio7i. Body subcylindric, fusiform; head cuneiform; snout elongated; lower jaw 

 straight ; back nearly straight. Eyes large, sub-oblong. Dorsal, anal and pectorals roundish ; 

 ventrals very small, roundish, situated midway between the anal and pectoral fins ; caudal 

 truncate. 



Color. Back and upper part of the head brown olive ; lower parts white. Sides with deli- 

 cate blue tints. Opercles with brilliant yellow and blue reflections. 



Length, 5"0. Depth, 0'6. 



Fin rays, D. 13 ; P. 18 ; V. 6 ; A. 12 ; C. 18 f . 



This is described by Lesueur from Saratoga lake, where it is used as a bait for other 

 fishes. 



