No. 437.| WORTH, AMERICAN INVERTEBRATES. 235 
drical, single chambered, much longer than height of bell. Arms eight, 
arranged in pairs, not longer than broad; each arm with 60-70 delicate 
tentacles. Eight marginal anchors. 
Color. — Black or dark brown, occasionally reddish- or yellowish-brown. 
Stze.— 5-7 mm., height including stem, 20-30 mm. 
Distribution. — Eastport, Me. (Stimpson), Swampscott, (Ag.), Greenland. 
SYNOPSIS OF THE FAMILIES AND GENERA OF PEROMEDUS&. 
Family PERIPHYLLID&. Rhopalia 4, marginal lobes 16, tentacles 12. 
Family Pericolpide. Rhopalia 4, marginal lobes 8, tentacles 8. 
A single genus only of the Peromedusz is represented within 
the range of the present synopsis, namely, Periphylla and under 
this three species have been recorded. 
Generic characters :— Umbrella with four perradial, buccal pouches and 
with four basal funnels; gastric 
pouches with two rows of filaments. 
Periphylla, hyacinthina Steenstrup. 
1837. 
Umbrella bell-shaped, about as 
broad as high; marginal lobes nearly 
right-angled truncated below; the 
eight tentacle lobes with about the 
same marginal dimensions as the 
rhopalial lobes; tentacles about 
double the length of the bell-height. 
Manubrium extending to the base of 
the marginal lobes, and about double 
as broad as high. 
Color—Exumbrella reddish, pedalia 
and marginal lobes red to violet, tenta- 
cles bluish. (Heckel.) ( 
Distribution. — Greenland, Steen- 
strup, Gulf Stream go—roo miles S. E. ( f 
off Martha’s Vineyard (Fewkes). Fig. 2. Periphylla peronii Heckel. 
