J. W. Fewkes—Medusa from New England. 125 
Rhopilema has sixteen small velar and two occular lappets in 
each octant, which is thought to be a sufficiently marked dif- 
ference to separate it from Nectopilema, which has six velar and 
two marginal lappets in each octant.* Moreover, Grenacher 
and Noll’s figure of Rhizostoma luteum Gren. & Noll, to which, 
according to Heckel, P. clavigera is related, differs from that 
of my Nectopilema so widely that I cannot think that my 
. genus is the same as his P. clavigera. 
There remains to be mentioned the relationship of Nectopr- 
lema to the genus Polyrhizu, a genus belonging, according to 
Heckel, not to the Pilemide but to the Zoreumide. Of all 
the Toreumide, Polyrhiza is the most closely allied to the 
Pilemide and to the sub-family Stomolophide. It certainly is 
not known, so well as might be wished, what is the structure 
of certain organs of Polyrhiza, nor what its true affinities 
are. Heckel has placed it in the family of Torewmidc, while 
Brachiolophus and Rhopilema are placed with the Pilemide. 
There are resemblances between Rhopilemat and Polyrhiza 
which imply their close relationship. As Nectopilema has 
strong resemblances to Fhopilema, it also has affinities with 
Polyrhiza Ag. I cannot, however, place it in this genus as at 
present defined. 
The following characters when combined are thought to dis- 
tinguish Nectopilema from other Pilemide: Six velar lappets 
in each octant; no tentacles; sixteen scapulettes; eight oral 
arms with numerous gelatinous filiform appendages, ‘t Gallert- 
knipfe.’ The genus is believed to belong to the Pilemide, 
connecting the Stomolophide and the Hupilemide. 
EXLPANATION OF THE PLATE. 
This Plate represents a side view of Nectopilema, showing the oral arms and a 
portion (quadrant) of the umbrella margin. As the bell was in fragments it was 
not possible to give its form, and therefore the relative extension of the oral 
appendages beyond the bell-margin may not be accurately represented. 
lu the medial line on the bell-margin a sense body is represented. On either 
side we have octants of the bell-margin with occular and velar lappets. 
The bodies seen behind the bell-margin are sexual bodies. Their extension is 
more or less conjectural. as they were more or less ruptured. ‘The leaf-like ap- 
pendages to the sides of the oral apparatus below the bell-margin are the scapu- 
leites. The lower part of the oral appendages or oral arms bear filamentous 
appendages or ‘ Kolbenformige Gallertknopfe.” 
The figure was drawn from nature by Mr J. Henry Blake. It is one-half 
natural size of the alcoholic specimen. 
* The marginal lappets correspond closely with those of Cramborhiza flagellata 
or macronema (both specific names given by Heckel in the same work, op. cit.). 
This genus (Cramborhiza), according to Heckel, is allied to Lychnorhiza, which 
has no scapulettes. j 
+ It is probable that the numerous ‘ Kolbenformige Gallertknépfe” of Rhopilema 
and the © Peitschen Filamenten’” of Polyrhiza are homologous. . 
Cambridge, Mass., Dec., 1886. 
