32 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [826] 
the body is much longer, and the tail is long, slightly tapered, straight, 
and obtuse. The Pontonema vacillatum also occurs in similar places in 
abundance. In this species the male has a short, obtuse, incurved tail ; 
the female a straight, tapering, narrow, obtuse one. Both species are 
oviparous, and the female genital orifice is near the middle of the body. 
These worms are from a quarter to half an inch or more in length, 
Their complete history is not known; they are closely allied to many of 
the parasitic worms, and it is possible that in some stages of their de- 
velopment these are also parasites. 
Of the Radiates there are also numerous species to be found on these 
rocky shores. 
Although the purple “ sea-urchin,” Arbacia punctulata, and the green 
“sea-urchin,” Strongylocentrotus Drobachiensis, (Plate XX XV, fig. 268,), 
are sometimes met with, their occurrence is irregular and uncertain at 
low-water in this region. The former occurs in abundance on rocky 
and shelly bottoms in the sounds; while the latter occurs chiefly on sim- 
ilar bottoms in the cold area, and at low-water on the outer rocky 
shores, and still more abundantly farther north. 
The green star-fish, Asterias arenicola, (Plate XXXYV, fig. 269,) is 
found in large numbers at low-water among the rocks at certain times, 
but at other times is seldom met with, though a few young specimens 
can almost always be found by careful search beneath the stones. The 
adults were very abundant on the shore at Parker’s Point, in the latter 
part of June; but by the middle of July very few could be found there. 
Their habit of coming up to the shore may be connected with their 
reproductive season., They are always abundant on shelly bottoms in 
the bays and sounds, especially where there are beds of muscles or 
oysters, upon which they feed. They often prove exceedingly destruc- 
tive of oysters planted in waters that are not too brackish for their com- 
fort. They manage to eat oysters that are far too large for them to 
swallow whole, by grasping the shell with their numerous adhesive feet, 
and then, after bending their five flexible rays around the shell so as 
partly to inclose it, they protrude the lobes and folds of their enormous 
saccular stomach from the distended mouth, and surrounding the 
oyster-shell more or less completely with the everted stomach they 
proceed to digest the contents at leisure, and when the meal is fin- 
ished they quietly withdraw the stomach and stow it away in its proper 
place. In this way a large “school” of star-fishes will, in a short time; 
destroy all the oysters on beds many acres in extent, unless their oper- 
ation be interfered with by the watchful owners. In one instance, 
within a few years, at Westport, Connecticut, they thus destroyed about 
2,000 bushels of oysters, occupying beds about 20 acres in extent, in a 
few weeks, during the absence of the proprietor. 
In order to stop their operations it is necessary to dredge over the 
eyster-grounds and destroy all the star-fishes thus brought up, by leav- 
ing them on shore above high-water mark ; for if simply torn in pieces 
