BIOLOGICAL STUDY OF CHESAPEAKE BAY WATERS 
365 
as Anoplodactylus lentus Wilson. It was collected at area G in the mouth of the bay 
during the May, 1920, cruise. The bottom salinity at this area was 25.77 per mille 
and the temperature 13.8° C. 
MOLLUSCA 
The rather large number of mollusca which have been collected by us are now in 
the hands of the United States National Museum, awaiting identification. 
ECHINODERMATA 
The echinoderms collected during the Chesapeake survey have been identified 
by Dr. Hubert Lyman Clark, to whom I am much indebted for a list of the species 
and additional information concerning their geographical distribution. 
The number of species is small, but no smaller than might be expected from a 
rather fresh estuary with a muddy bottom. All of the specimens collected, with one 
exception, were found either in that part of Chesapeake Bay below the mouth of the 
Potomac River (most of these were taken not far from the mouth of the bay) or just 
outside of the bay a short distance. 
A list of the species follows: Asterias jorbesi (Desor), Stephanaster gracilis (Per- 
rier), Echinarachnius parma (Lani’k), Amphiodia sp., Amphipholis sguamata 
(Delle Chiaje), and Amphioplus abdita (Verrill). In addition to these echinoderms, 
which were identified by Clark, a few specimens of the holothurian, Thy one briareus 
(Lesueur), the common red sea urchin Arbacia punctulata (Lam’k), and the starfish 
Luidia clathrara (Say) have been found. 
The echinoderm, which was captured by far the largest number of times in Chesa- 
peake Bay during the cruises of 1916, 1920, 1921, and 1922, was the common starfish 
Asterias for besi, which was brought to the surface on 54 occasions. It was collected 
during the following cruises: April, June, July, September, 1916; January, March, 
May, July, December, 1920; January, March-April, May-June, 1921; and January, 
March, 1922. Undoubtedly it may be found in the bay any time during the year but 
ordinarily only in the region below the Maryland and Virginia line. It has been taken 
at areas E, F, and G in the mouth of the bay, at area G' off Old Point Comfort, at 
various localities between these two regions, at areas A, B, C, and D, which mark a 
line from Cape Charles City to New Point Comfort, and at areas Q and 0. It will 
be seen that no specimens were collected above the line marked by areas H, H' , Q, 
and 0, which runs from the mouth of the Rappahannock River to Sandy Point. 
Apparently this form can stand a considerable range of salinities and temperatures, 
for it was found on bottoms where these ranged from somewhat less than 20.00 to 
32.00 per mille and 4.2° C. to 24.4° C. Specimens were taken at depths from 8 
meters at area Q to 46 meters at area A. Frequent catches were made at the latter 
area, and these were in general the largest made in the bay. The Biological Survey 
of Woods Hole and Vicinity (Sumner, Osburn, and Cole, 1913, pp. 111-112) showed 
that A. jorbesi was encountered with the most frequency of any echinoderm in that 
region and that it together with Arbacia . punctulata were the ones taken most often in 
Buzzards Bay. Similarly in Chesapeake Bay A. jorbesi was the form most frequently 
encountered. 
Judging from our collections, the starfish Luidia clathrata seldom enters the bay. 
Only on two occasions has it been taken — once in January, 1916, at area H and once 
in July, 1916, at area F. 
