CTENOPHORES IX NEW JERSEY COASTAL WATERS. IO7 



Bigelow obtained his specimens off the New Jersey coast in July, 

 whereas Mayer and I found our ctenophores in October. The 

 three distinguishing characters of P. brnnnea as established by 

 Mayer are clearly evident even to one who is but little familiar 

 with the characteristics of this group. The chief question would 

 seem to be whether this organism should be raised to specific 

 r.mk, or be included as a variety of P. pile us or of Tlonuiphora 

 Spatulata. Its appearance in New Jersey coastal waters in 

 October would seem to point to its being essentially a cool water 

 form and hence closer to P. pileus. 



Tin- ran^e of Mnemiopsis leidyi is given by Mayer as from the 

 southern coast of New England south to the Carolina-. It is 

 considered by Mayer to be a ctenophore of the pure sea water 

 alonu tin- outer shores; its place being taken in the brackish 

 \\atcr by it- much smaller relative, M. gardeni. Bigelow ('15) 

 u ith tlii- from his own findings. Nowhere in the accounts 

 it her of these investigators do I find evidence that they made 

 any eaivlnl examination of the estuaries of the New Jersey coa-t 

 for i In ir .17. leidyi occurs in abundance for months at a tinu in 

 \\atcr of .1- low as one-third the salinity of the sea or even below 

 tin-. < >n one occasion I found it in upper Delaware Bay. just 

 U-lou Siony Point, in water of a specific gravity less than 

 1.005. 



That I have not confused .17. leidyi with M. gardeni will be 

 e\ idrin from the following: (i) M. gardeni is described by 

 M yet as being 35-40 mm. in length when mature. I ha\ 

 found Mnemiopsis over 100 mm. long in Barnegat Bay. (2) The 

 oral loin - of .17. gardeni are very small, from one-fifth to one-sixth 

 as loti'c as the body. In all specimens of Mnemiopsis which I 

 ha\c -ttii, excepting only immature individuals not yet fully 

 cmnxrd into the Mnemiopsis stage, the oral lappets are much 

 longer than this and they flare widely. (3) My specimens show, 

 \\hen large numbers are together, a decided pinkish hue, not the 

 blui-h color of M. gardeni. (4) The range for M. gardeni as gixen 

 by Ma\i-r i- from Chesapeake Bay to Florida. (5) the striking 

 power of adaptation of our species to low temperatures argues 

 against its bein- the southern form. (6) I do not find in my 

 specimens the -mail low discoidal warts on the oral lobes which 

 according to Mayer are characteristic of M. gardeni. 



