CTEXOPHORES IX XEW JERSEY COASTAL WATERS. 95 



all the information I am able to gather this ctenophore appears 

 in New Jersey estuaries for a brief period during October, and 

 then disappears. Mr. Gray informs me that with one possible 

 exception Pleurobrachia (supposedly P. pileus] was not seen in 

 Wood- 1 lole at all in 1923. That it did not occur in Great Bay 

 during the summer of 1921 I am certain, since our floating labo- 



ry was stationed during this period but a few hundred yards 

 tr< Mil the place where myriads of these ctenophores were observed 

 in 1920. 



My first record for Beroe is November 4, 1920, when one half 

 .vn specimen was taken in Great Bay; the water temperature 



13 C, specific gravity, 1.0216. No further specimens were 



i until October 22, 1921, when 2 large individual-- were 

 ol,-er\ed in Little Kgg Harbor with temperature of 12.5 C., 

 -pe. ill.- gravity 1.0245. Xo Beroe were found in Little Egg 

 II. ul M.I during the autumn of 1922, nor in Barnegat Bay in the 

 autumn of 1923. A few large specimens were taken in the 

 latter region September u, 1924, water temperature 16.5 C., 

 and by the close of the month they were abundant. This 

 cienophore appeared in vast swarms, in the Maurice Ri\n, 

 1 >ela\\ are I'. ay, about the middle of September 1922 and again at 

 the >ainc time in 1923 and in 1924^ It was reported that at 

 times during the flood tide the Beroe were so abundant as almost 

 to form o 'iitimious rafts. In each of these years the ctenophores 

 appeared about the second week in September while the water 

 temperature was above 20 C. and remained very abundant until 

 early in October when they disappeared as quickly as they had 

 come. 



My records of Mnenriopsis are much more extensive than in 

 the case of the two preceding ctenophores. The data illustrate 

 in a >t rikin- way what other investigators have noted regarding 

 the intermittent appearance of the sea walnut. During the 

 summer- from 1908 to 1917 I frequently noted the presence of 

 Mnemiopsis, but being occupied with other problems kept no 



id of its occurrence. From early in 1919 to the present 

 careful records have been kept of the appearance and relative 

 abundance of the ctenophores. Search for these organisms has 



1 I am indebted to two of our former students, Mr. C. A. Perry and Mr. \Y. H. 

 Dumont. tor making ; -ervations and for sending specimens for identification. 



7 



