126 GENUS HYDRARGIRA. [October. 



covering on the spire, and sometimes on the body, which 

 completely obscures the obsoletely wrinkled epidermis; 

 aperture ovate-orbicular; suture impressed. 



Length three twentieths, breadth one tenth, of an 

 inch. 



Cabinet of the Academy. 



Animal whitish; head brown; mouth, tentacula, orbits, 

 and vitta on each side of the neck, white; tentacula filiform, 

 more than half as Ipng as the base of the animal; rostrum 

 about lialf as long as the tentacula, annulate with darker 

 lines above; foot white, brownish above, short, suboval, 

 truncated before, and rounded behind. 



Extremely numerous on the muddy shores of the ri- 

 vers Delaware and Schuylkill, between high and low wa- 

 ter mai'ks. 



Descriptions of four new species, and two varieties, of 

 the genus Hydrargira. By iJ, A, Le Sueur, Read Octo- 

 ber 2\, 1817. 



Along the muddy shores of the fresh water streams of 

 the United States, and in the ponds of the ^alt marshes of 

 the coast, the^e are found small fishes, which are known 

 under the popular names of Mud Fishes, and Minows, in 

 consequence of their habitudes, and diminutive appccW- 

 ance. These fishes affect those situations which are well 

 supplied with aquatic plants, or where old logs lie imbed- 

 ded in the mud, which situations afford them shelter from 

 danger, on the least appearance whereof they quit, with 

 precipitation, their open stations near the surface of the 



