336 
BULLETIN OP THE BUREAU OP FISHERIES 
four of the large number of surface towings yielded any specimens. These, only 
10 specimens in all, were mostly small. 
The towings from the March-April cruise possibly show the culminating effect 
of the inflowing bottom current characteristic of the fall and winter months, by 
the very large catches of Sagitta elegans; although the large numbers of small speci- 
mens, some of them only 1 or 2 millimeters long, in addition to many large specimens, 
even in the upper part of the bay indicate that the great abundance was due in part 
to breeding taking place in the bay. A large number of the specimens collected 
during the March-April cruise were in good condition but some of the larger speci- 
mens were shrunken. Whether this condition indicated the passing of the breeding 
season for those individuals, or whether it was the result of the effect of low salinity, 
I am not prepared to say. The following data for the bottom net (10-minute towings) 
which must be considered as covering only the upper half of the bay since no surface 
or bottom towings were made south of the mouth of the Potomac River or more 
precisely south of areas R' and R off Barren Island, show that the catches (given 
in round numbers) were much larger in that region than those of any other 
cruise: Area R', 70 specimens, the largest of medium size and grading down to 2 
millimeters in length; area R, 2 specimens; area T, 120 specimens of medium size; 
area S, 1,850 specimens (nine 26 to 28 millimeters long, 1,841 grading down to 1 
to 2 millimeters in length); area V, 26 specimens in poor condition (salinity not 
over 9.16 per mille, shallow area, 9 meters in depth); area Z, 7 specimens, one 22 
millimeters long; area Y, 1,650 specimens, the largest 31 millimeters long and grading 
down to 2 millimeters in length. This surprisingly large catch at area Y, which 
is off Love Point, not far from Baltimore, was made in water the salinity of which 
was not higher than 12.99 per mille. On the same day about two hours earlier 
one of the two largest catches of Copepods for all the cruises was made at area Z 
close by. 
The catches of Sagitta elegans taken in Chesapeake Bay are of interest because 
of the large numbers of small specimens and the small numbers of large specimens, 
the latter being limited to the January and March-April cruises. The capture of 
only one specimen reaching 31 millimeters in length indicates that this species does not 
grow as large in the Chesapeake Bay region as farther north, where it is colder, and 
supports the conclusions of Huntsman (1919, p. 447) and Bigelow (1926, p. 320) that 
the size of S. elegans is dependent upon the temperature. Another point of interest is 
the occurrence of some very small specimens of S. elegans, at least during all of the 
cruises (July, August, October, December, 1920, and January, March-April, 1921), 
even though limited to the mouth of the bay. Such a condition indicates that S. 
elegans breeds continuously during those months, outside or inside of the bay, and 
leads to the suspicion that it may breed to some extent throughout the summer off 
Chesapeake Bay, as Bigelow (1926, p. 314) has found to be the case on the Georges 
Bank. 
Owing to the fact that the so-called “bottom net” used on our cruises was not 
of the closing variety, no definite information can be had as to the vertical distribution 
or as to the precise salinity in which specimens brought up in that net lived. The 
scarcity of specimens in the surface nets during all cruises shows clearly, however, 
that Sagitta elegans was almost confined to lower layers during the daytime, at least. 
All of the towings in the bay were made in the daytime. The studies of Huntsman and 
Reid (1921, p. 12) in the estuary known as the Magagnadavic River show that there 
