178 REPORT OF COMMISSIONER OF FISH AND FISHERIES [472] 
Lamellibranchs. 
Page. | Page 
Pholas truncata.......---- 470| Callista convexa.....-..... 470 
P. costata ......------0--- 433| Mulinia lateralis .......... 470 
Mya arenaria .....-------- 469} Solenomya velum ... ..... 470 
Macoma fusca .......-.--- 469| Nucula proxima........... 432 
Tellina tenta........------ 470; Argina pexata..........-. 309 
An gulustener ie ls a ett es ah 358 Modiola plicatula ee eee 469 
Tagelus PID. «cs v0 an oo os 470| M. hamatus............-.. 374 
Petricola pholadiformis.... 470 Mytilus edulis............. 470 
Venus mercenaria......... 469 Ostrea Virginiana ........ 310 
III. 3.— ANIMALS INHABITING OYSTER-BEDS IN BRACKISH WATERS. 
Although the oyster-beds are generally planted on bottoms that were 
originally muddy, when covered wholly or partially with living oysters or 
with dead oyster-shells, such bottoms may properly be regarded as “‘shelly 
bottoms” analogous to the natural shelly bottoms of the outer waters. 
The shells of the oysters afford suitable attachment for various shells, 
bryozoa, ascidians, hydroids, sponges, &c., which could not otherwise 
maintain their existence on muddy bottoms, while other kinds of ani- 
mals, such as crabs, annelids, &c., find shelter beneath the shells or in 
their interstices. Some species have apparently been introduced from 
farther south with the oysters; among these are Modiola hamatus and 
Panopeus Herbstii, neither of which is positively known to be fully nat- 
uralized on our shores. 
In planting the oysters they are more or less uniformly scattered over 
the bottom, from somewhat above low-water mark to the depth of ten 
or twelve feet. The oysters thus planted are brought mostly from the 
waters of Virginia and Maryland in spring. During the summer they 
usually increase greatly in size, and often become very fat and improve in 
flavor. They are taken up in the fall, for if left exposed to the freezing - 
weather of our winters, at least all those in very shallow water would be 
killed. They often double in bulk during the summer. Besides the im- 
mense quantities of oysters thus brought from farther south to be “ plant- 
ed” in our waters, large quantities of young “ natives” are also collected 
from the localities where they naturally breed, and are planted on muddy 
bottoms in the brackish waters, where they grow very rapidly, usually 
attaining a size suitable for the market in two or three years. 
These ‘‘ native oysters,” although of the same species as those brought 
from the south, are more hardy, and will live through the winter if cov- 
ered by a depth of water sufficient to prevent them from freezing. The 
young oysters that attach themselves to stones, ledges, &c., between 
tides, often in great abundance, nearly all perish by freezing during the 
winter. They mostly become an inch to an inch and a half in diameter 
during the first summer. The period of spawning lasts for some time, 
