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BULLETIN OF THE BUREAU OF FISHERIES 
January cruise and a great scarcity in March. While the discussion just given is not 
based on a careful quantitative study of the abundance of the ctenophores, the fact 
that there is close agreement between the observations made by Radcliffe in 1916 and 
by the author in 1920, 1921, and 1922 as to relative abundance makes the conclusions 
of considerable value. The evidence all supports the view that a scarcity of full- 
grown specimens, at least, occurs during the spring months (for example, March, 1916, 
1920, 1921, and 1922), that the numbers increase in early summer, that they reach a 
maximum in the late summer and fall, and that during part of the winter they are 
still present, widely distributed. In the late fall and early winter the writer has found 
them several miles up the Severn River. 
Our observations on the seasonal occurrence of ctenophores in Chesapeake Bay 
are in rather close agreement with those made by Nelson (1925) for the inland coastal 
waters of New Jersey. 
VERMES 
NEM ATHELM INTHES 
NEMATODA 
The collection of nematodes, which is large, is now in the hands of Dr. N. A. 
Cobb, senior nematologist of the Department of Agriculture. He has been working 
on them for some time and finds that the five hundred and odd specimens comprise 
at least a dozen genera (Oncholaimus, Chromodora, Euchromodora, Enoplus, Anti- 
coma, Spilophora, Monbystera, etc.). The number of species he states are “upward 
of 20, some of them doubtless new.” No further discussion of this group can be made 
at the present time. 
CHAETOGNATHA 
The occurrence of sagittas, ordinarily thought of as marine planktonic forms, in 
the waters of Chesapeake Bay is not surprising when it is known that one species at 
least has been found in the Baltic Sea (Apstein, 1911, p. 174; Ritter-Zahony, 1911, 
p. 19) and since the investigations of Huntsman and Reid (1921, pp. 10-14) have 
shown that Sagitta elegans was found in brackish water estuaries where the salinity 
was probably as low as 20 per mille. Three species Sagitta elegans Verrill, Sagitta 
serratodentata Krohn, and Sagitta enflata Grassi represent the sagittas collected during 
the cruises of July, August, October, December (1920), and January, March-April 
(1921). The writer made the identifications following the classifications of Ritter- 
Zahony (1911) and Huntsman (1919), although no attempt was made to distinguish 
subspecies. Of the three species mentioned, specimens of Sagitta elegans were by far 
the most abundant, and specimens of S. serrotodentata barely made their appearance 
inside of the bay. 
The studies of Huntsman (1919), Bigelow (1922, 1926), and myself all lead 
to the conclusion that Sagitta elegans is primarily a neritic form. This species, 
however, was all but absent from Chesapeake Bay during the July and August 
cruises, judging from numerous surface (over 100), and bottom towings (over 40), and 
vertical hauls (30) made at widely distributed areas. Only at areas G in the mouth 
and B near by were any specimens captured. All of these were small forms varying 
from about 4 millimeters to 10 millimeters in length, and only one specimen was 
taken in the surface nets. Additional evidence indicating a scarcity during the 
summer is afforded by the records in the log for the May-June cruise of 1921, which 
