[49] FISHEEIES OF THE UNITED STATES. 233 



penetrate the sand much faster than the spade can follow them. Even 

 when partially uncovered they often hold themselves so firmly in the 

 holes by means of their muscular foot, that the body can be entirely 

 withdrawn from the shell before the hold is relaxed. As their siphons are 

 very short, they are obliged to come to or near the surface in order to 

 obtain the necessary supplies of oxygen and food. Therefore, though 

 the animal may be out of sight, yet it is probably only sunk a short 

 distance in the sand, and a sudden thrust of a spade obliquely across 

 the direction of the burrow will frequently unearth the clam. The dis- 

 advantages of the short siphons are, however, made up by the great 

 activity of the animal and the wonderful power of its foot, which is its 

 excavating implement and organ of locomotion. 



The razor-clam is eaten to some extent along the coasts of Long Island, 

 Long Island Sound, Massachusetts Bay, and coasts of New Jersey. It 

 is to be found in the New York markets, but the trade is not extensive, 

 the sweetish flavor of the flesh being unpalatable to the majority of 

 people. It is used as bait, also, especially about Cape Cod and on the 

 south shore of Long Island, and is devoured by several fishes, such as 

 the skates and tautog, that seem to have the power of rooting it out of 

 the sand. The New Jersey longshoremen also claim that the " winkle" 

 {Fulgur carica) has the power of pulling the "razor" from its burrow 

 and devouring it. 



Venus mercenaries Linne\ 



This is the "quahaug," or "round clam," sometimes known as the 

 " hard clam." It is found from Florida to Massachusetts Bay, and thence 

 northward, though rare and local, to the Gulf of Saint Lawrence. It is 

 very common from Vineyard Sound southward, and is found fossil in the 

 Post-Pliocene formations of Massachusetts, Gardiner's and Nantucket 

 Islands, Virginia and South Carolina, and in the Miocene of Maryland, 

 Virginia, and North and South Carolina. This species lives chiefly on 

 muddy and sandy fiats, just below low- water mark ; but it is often found 

 above that line, and between tides is frequently left bare. It is more 

 abundant in estuaries than elsewhere. It can burrow but a short dis- 

 tance, having short siphon-tubes, and it is often seen crawling about on 

 the surface by means of the broad, muscular foot with which it excavates 

 its burrow. The shells are variable in color and form, and early writers 

 have made many varieties of this species on that account. Some forms, 

 especially those growing in estuaries, have dull, thick, rough shells, 

 sometimes white, sometimes stained, while shells from outer, sandy 

 beaches are thinner and more delicate, have raised, concentric ridges 

 or ribs, and are marked with streaks of brown or red. Other shells 

 have marked dark blue or purple discolorations outside the pallial line; 

 others are of dead white. All these have been described as distinct 

 species, but there is no structural difference ; and intermediate forms 

 are to be found in every locality. As these clams grow old, the valves 



