106 THURLOW C. NELSON. 



accepted ideas regarding the habitat of these species. All are 

 usually considered as being strictly oceanic forms, and yet I 

 have taken them in waters ranging from one half to less than a 

 third the salinity of their supposed usual environment. 



Mayer '12 holds that there are but two dominant species of 

 Beroc, B. ciicumis of cold waters and B. ovata of warm water. 

 B. forskali, which was found at numerous stations by Bigelow, is 

 believed by Mayer to be but a variety of B. ovata. Bigelow ('15) 

 lists B. ciicumis from 7 stations at some distance from the coast of 

 New England. He does not record it off the New Jersey coast in 

 July, nor does he mention B. ovata. 



Mayer ('12) notes that the young of B. ciicumis cannot be 

 distinguished from those of B. ovata. In the adult the peripheral 

 network of vessels arising from the meridional canals freely 

 anastomoses in B. ovata, remaining distinct in B. cucumis. 



Pleurobrachia brunnea, a species created by Mayer '12 to 

 receive a ctenophore found off the New Jersey coast in October, 

 1904, is of somewhat doubtful position. Bigelow ('12) believed 

 this to be so close to Hormiphora spatulata Chun, as to be identical 

 with it. In a later publication ('15) he throws still further doubt 

 on the validity of the species, believing it to be well within the 

 limits of P. pileus, a ctenophore of wide distribution which he 

 found in great numbers off the New Jersey coast in July 1913. 



The characters used by Mayer to establish P. brunnea as 

 distinct from P. pileus are: the continuation of the 8 meridional 

 canals for a considerable distance downward beyond the ciliary 

 combs; the yellow color of the stomodeum; and the knobs on 

 the ends of the tentacles. It is distinguished from Hormiphora 

 spatulata by the knob-like ends of the tentacles; and by the fact 

 that its ciliated combs begin at a greater distance from the apex 

 than in II. spatulata. 



My own specimens agree in every particular with Mayer's 

 description and figure of P. brunnea, the yellow color of the 

 stomodeum and the knob-like ends of the tentacles being quite 

 striking in the living specimens. The downward continuation of 

 the meridional vessels below the ciliary combs is clearly evident 

 in the preserved as well as in the living specimens. In con- 

 sidering Bigelow's belief that this form may lie within the limits 

 of variation of typical P. pileus it is well to remember that 



