114 



bulletin: museum of comparative zoology. 



growth of the gonophores in this position is due to the change in posi- 

 tion of the support of that particular part, the whole growth of these 

 must have taken place after the colonies had been torn away. 



Another instance is here exhibited of the ready interchange of the 

 various parts of the colony and, here as well as in Clytia cylindrica, 

 of considerable power of adaptability to varying conditions. 



Medusae, siphonophores, ctenophores. 



The identifications in the table (p. 316-317) require explanation. 

 All with broad stomach, smooth subumbrella and considerable 

 numbers of tentacles and canals are classed here as Ae. aequorea. 

 ■Aequorea groenlandica Peron et Lesueur. I follow Mayer (1910, p. 



Fig. 78. — Obelia geniculata. 



335) in identifying as a southern race of Ae. groenlandica the large 

 aequorid, with stiff gelatinous substance, and numerous subumbral 

 gelatinous papillae radially arranged, which is common off the coast 

 of New Jersey in summer and autumn. The southern race has been 

 recorded so seldom that a few counts of the radial organs are given: — 



Station 



10069 

 10075 



Canals 



89, all with gonads 

 96, 3 branched 

 88, 1 

 106, all simple 

 85, all simple 



Aglantjia digitale Fabricius. The status of the two forms of Aglan- 

 tha, so often recorded from northern waters as " rosea" and " digitale," 



