310 REPORT OF^SMMISSIONER OF FISH AND FISHERIES. 



met with at low water, under or among rocks, and generally attached 

 by a byssus, bnt tbeir proper home is in the shallow waters off shore, 

 especially on muddy, shelly, and gravelly bottoms. The fishermen call 

 them "bloody clams," because the g^lls are red, and when opened they 

 discharge a red fluid like blood. The little shell called KelUa planulata 

 (Plate XXX, fig. 226) is also sometimes found under stones at low 

 water. Attached to the sides and surfaces of rocks and ledges along 

 many parts of this coast, young oysters, OstrlXfi Virginiana, often 

 occur in vast numbers, sometimes completely covering and concealing 

 large surfaces of roclcs. But these generally live only through one 

 season and are killed by the cold of winter, so that they seldom be- 

 come more than an inch or an inch and a half in diameter. They come 

 from the spawn of the oysters in the beds along our shores, which, dur- 

 ing the breeding season, completely fill the waters with their free- 

 swimming young. They are generally regarded as the young of "native" 

 oysters, but I am unable to find any specific differences between the 

 northern and southern oysters, such differences as do exist being due 

 merely to the circumstances under which they grow, such as the char- 

 acter of the water, abundance or scarcity of food, kind of objects to 

 which they are attached, age, crowded condition, &c. All the forms 

 occur both among the northern and southern ones, for they vary from 

 broad and round to very long and narrow ; from very thick to very 

 thin ; and in the character of the surface, some being regularly ribbed 

 and scolloped, others nearly smooth, and others very rough and irregular, 

 or scaly, &c. When young and grown under favorable conditions, 

 with plenty of room, the form is generally round at first, then quite 

 regularly oval, with an undulated and scolloped edge and radiating 

 ridges, corresponding to the scollops, and often extending out into 

 spine-like projections on the lower valve. The upper valve is flatter, 

 smooth at first, then with regular lamellte or scales, scolloped at the 

 edges, showiug the stages of growth. Later in life, especially after the 

 first winter, the growth becomes more irregular, and the form less sym- 

 metrical ; and the irregularity increases with the age. Very old sped' 

 mens, in crowded beds, usually become very much elongated, being 

 often more than a foot long, anil perhaps two inches wide. In the 

 natural order of things this was probably the normal form attained by the 

 adult individuals, for nearly all the oyster-shells composing the ancient 

 Indian shell-heaps along our coast are of this much-elongated kind. 

 Nowadays the oysters seldom have a chance to grow to such a good old 

 age as to take this form, though such are occasionally met with in deep 

 water. The young specimens on the rocks are generally mottled or ir- 

 regularly radiated with brown. They were not often met with on the 

 shores of Vineyard Sound, for oysters do not flourish well in that sandy 

 region, though there are extensive beds in some parts of Buzzard's 

 Bay, and a few near Holmes's Hole, in a sheltered pond. The oysters 

 prefer quiet waters, somewhat brackish, with a bottom of soft mud 



