366 
BULLETIN OF THE BUREAU OF FISHERIES 
At least two species of brittle stars were found in Chesapeake Bay. One, 
Amphioplus abditus, was taken in August, 1920, at areas G, F, and E — that is, in the 
mouth of the bay at depths from 16 to 24 meters. The bottom salinities at these 
areas were all above 30.00 per mille and the temperatures ranged from 15.5° C. to 
20.9° C. The other species, Amphiodia sp . ? (probably atra Stimpson according to 
Clark), was found at area B during the same cruise at a depth of 13 meters. At this 
area the bottom salinity was 24.34 per mille and the temperature 25.0° C. 
One species of sea urchin, Arbacia punctulata was taken on six of the cruises 
(June-July, 1916, December, 1920, and January, 1921). Without exception they 
were found in the mouth of the bay and in four out of six cases at area G where the 
bottom salinities and temperatures varied approximately from 29.00 to 32.00 per 
mille and 5.9° C. to 21.0° C. 
The holothurian, Thyone briareus, showed a somewhat more extensive distri- 
bution in Chesapeake Bay than the rest of the echinoderms. Specimens were found 
at areas A, B, G' , G, and P during the cruises of January and May, 1920, May-June, 
1921, January and March, 1922. It will be seen that while most of the specimens 
were taken in the lower part of the bay, one was found a short distance above the 
mouth of the Potomac River (area P). The indications are that this form is able to 
stand a wide range of salinities and temperatures. Three other echinoderms are 
listed above as having been captured during our cruises, but all of these were found 
outside of the bay between the mouth and the 118-fathom line (216 meters). The 
starfish, Stephanaster gracilis, the common sand dollar, Echinarachnius parma, and 
the ophiuroid, Amphipholis squarnata, were all found on the same cruise, August, 
1920, along the 118-fathom line. The latter was also brought up along the 43-fathom 
(79 meters) and 20-fathom (37 meters) lines during the same cruise. 
It is worthy of note that five species of echinoderms, S. gracilis, E. parma, Aphi- 
pholis squarnata, Amphioplus abditus, and Amphiodia spA were taken during the 
August, 1920, cruise when a trip to the 118-fathom line was made in addition to usual 
trips over the bay. 
A review of the eight species of echinoderms shows that only two species, Asterias 
jorbesi and Thyone briareus have been found far inside the mouth of Chesapeake Bay. 
Through the courtesy of Dr. Hubert Lyman Clark I have received the following 
information concerning the distribution of some of the species: Speaking of the star- 
fish, Stephanaster gracilis, and the sand dollar, Echinarachnius parma, he says of the 
former, “A West Indian species. Its occurrence in Chesapeake Bay is noteworthy”; 
and of the latter, “A northern species. Its occurrence at the same station with the 
preceding species is noteworthy.” At the time the above was written Doctor Clark 
had not been informed that the station in question was outside of the mouth of the 
bay. However, undoubtedly, the occurrence of a West Indian and a northern species 
at the same station, even outside of the bay, is worthy of note. Concerning the species 
of Amphiodia he says: “ * * * the Amphiodia is perhaps the most important of 
your captures. If it is atra, as seems probable, its type locality is Charleston, S. C.” 
CHORDATA 
HEM I CHORDATA 
Fragments of a species of Balanoglossus, probably Dolichoglossus kowalevski 
(A. Agassiz), have been brought up by the beam trawl and orange-peel bucket. 
These came from about 1 1 meters off Lynnhaven Roads and from somewhat deeper 
water off the mouth of the Potomac River. The salinities and temperatures at the 
