BIOLOGICAL STUDY OF CHESAPEAKE BAY WATERS 
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show that no sagittas were seen in any of the unpreserved samples as they came to 
the surface. Such a condition suggests that the sagittas are really immigrants into 
the bay. It is of much interest to find that the towings of the October cruise revealed 
considerably larger numbers of S. elegans in Chesapeake Bay than those of the summer 
cruises, and also to recall that this cruise took place during the time of year when 
there was a strong tendency for the deeper and more saline layers to move into the 
bay. The records, which deal with the usual large number of surface and bottom 
towings, show that all the specimens were small, about 4 to 10 millimeters in length, 
and that they were distributed as far north in the bay as area X. While there were 
many surface towings made, all of the specimens came from the bottom net (which, 
however, was not a closing net), indicating that S. elegans was confined largely to 
the deeper and more saline waters in the daytime, at least when all the samples were 
taken. By far the largest catches were in the mouth of the bay, and the numbers 
showed a fairly uniform decreasing range for the successive areas passing toward 
the head. The following data for the bottom net (10 minutes towing) illustrate 
this: Area G, 927 specimens, largest 6 to 7 millimeters long; area F, 805 specimens of 
about the same size as those for area G; area A, 5 specimens 4 to 7 millimeters long; 
area B, 33 specimens mostly about 8 to 10 millimeters long; area C, 16 specimens 
about 8 to 10 millimeters long; area Q, 42 specimens ranging up to 10 millimeters 
long; area H ' , 5 specimens 4 to 7 millimeters long; area I, 3 specimens about 6 tolO 
millimeters long; and area X, 1 specimen about 9 millimeters long. No large 
specimens were found. 
While it is probable that Sagitta elegans breeds to some extent in the bay, 
the absence of large specimens during the October cruise, the large number of young 
specimens in the waters of the mouth of the bay with a decreasing number farther 
in, the autumnal hydrographic conditions, and at the time of the July and August 
cruises an almost complete absence of it from the hauls, indicate that the bulk of 
the specimens found during the October cruise were being transported gradually 
from their breeding place, probably just outside of the capes, into Chesapeake Bay. 
The towings of the December cruise showed no large numbers of Sagitta elegans, 
nor was the distribution over the bay extensive. In fact, practically all of the speci- 
mens were taken in the mouth of the bay and close by. Only small individuals, 
from 3 to 11 millimeters in length, were captured, although the usual number of 
towings was made. 
During the January (1921) cruise, the usual, numerous towings all over the 
bay brought in rather large numbers in the lower half of the bay — that is, from area 
J to the mouth — but north of area J no specimens were captured, although many 
surface and bottom towings were made. At this time specimens of Sagitta elegans 
of rather large size, as much as 25 millimeters long, were taken, but in addition there 
were many smaller individuals which graded down to 4 millimeters in length. A 
good idea of the character of the catches may be had from the following data for 
the bottom net (10-minute towings): Area F, 106 specimens (seven 20 to 25 milli- 
meters long, 79 larger than any captured in earlier cruises but none 20 to 25 milli- 
meters long, and the rest of the 106 graded from 6 to 10 millimeters long); area E, 
17 specimens (six 15 to 21 millimeters long and eleven 4 to 10 millimeters long); 
area B, 60 specimens grading from 5 to 24 millimeters long; area C, 1 specimen 17 
millimeters long; area Q, 1 specimen 25 millimeters long; area H, 4 specimens, the 
largest 17 millimeters long; and area J, 3 specimens 20 to 22 millimeters long. Only 
