204 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
II. What is the geographical and bathymetrical distribution f 
The reply to this question will indicate the area subject or most liable to invasion. 
The purple star ranges from Labrador (probably farther north) to Cape Hatter as, and 
is most common north of Cape Cod. The common star ranges from Maine to the 
Gulf of Mexico, and is the species most common south of Cape Cod. The bathymet- 
rical distribution of the purple star is from high water to 208 fathoms, and of the 
common star from high water to 20 fathoms. 
From the numerous dredging expeditions of the U. S. Fish Commission launches 
and the steamer Fish Hatch carried on in 1898 it appears that in Narragansett Bay the 
purple star-fish (Asterias vulgaris ) is practically restricted to the lower portion of the 
bay, below Gould Island, though occasionally, perhaps, taken farther north. One, for 
instance, was taken near Dyer Island, among 1,000 or more of the common species. I 
have never known a single one among the thousands of bushels of star-fish captured 
on the oyster-beds in the upper half of the bay. The common star, on the other hand, 
occurs in greater or less abundance everywhere from Fox Point to the mouth of the 
bay, and is the only species that commits depredations upon our oyster-beds. (The 
purple star would doubtless be destructive if it were present.) The stars from the 
vicinity of the oyster- grounds are, moreover, very similar to one another in appearance, 
as compared with those collected in one locality at Woods Hole, where one haul of the 
mops may bring up stars which apparently belong to several quite different varieties. 
There are other varieties differing from those on our oyster-beds and from the 
purple star, which seem to be characteristic of certain localities. Thus, at the head of 
Buzzards Bay, at ISTeys Neck, a large number of common stars were collected, which 
were very similar to one another, but quite different from those on our oyster-grounds. 
They had very large coarse spines and were of a bronze color. The specimens taken 
by the Fish Hatch in waters south of Narragansett Bay seem to constitute a variety 
(maroon star) which occupies this area to the exclusion of other kinds. 
It is not known certainly whether each of these so-called varieties is an actual 
variety in the sense that the individuals breed true, or whether the peculiar appear- 
ance is due merely to the fact that the individual stars are bred and reared in a 
particular locality. If it should prove to be true that the young of a certain variety, 
e. g., the maroon star, are always like the parent stars, no matter where they grow, 
we might be able to determine to what extent the star-fish are dispersed while in 
the free-swimming larval condition. 
MODE OF LIFE. 
III. What is the method of locomotion t (It is possible that some barrier might be 
arranged that would limit , if not prevent, invasion.) 
The star-fish crawls or glides over submerged surfaces by means of the very 
numerous u suckers,” or feet, which protrude from the furrows on the under side of 
the arms. Small stars, A- inch or less from tip to tip, are frequently seen, ventral side 
uppermost, moving along with their suckers reaching up to the surface of the water. 
This performance can be carried on only when the water is very quiet, and is not often 
observed outside the aquarium. The buoyancy of the water and the great number 
of sucking feet enable the animal to crawl over the softest silt and the smoothest 
hard surfaces with ease, while the remarkable suppleness of the body enables it to get 
through incredibly small crevices. Besides this ordinary mode of locomotion, another 
