HYDROZOA 123 
like network over a surface and develops at intervals 
projecting points on which the zodids live. Each 
colony consists of feeding members, of reproductive 
members, and of a third kind which seems to have 
a protective function. These last are more slender 
than the others, and are without tentacles, but are 
armed with lasso- or stinging-cells. The colonies are 
of different sexes, the male being lighter in color than 
the female colonies. The eggs develop into planule, 
which swim about for a while and then give rise to 
other colonies. It is found from New Jersey north- colony of Coryne, 
ward, and is very abundant in Long Island Sound. Aatutal, size, 
Genus Coryn 
C. mirabilis. A hydroid about one inch high, growing in patches 
and appearing like tufts of moss on rocks between tide-marks. When 
highly magnified it shows club-shaped tubes with pedicels, terminating 
in zodids, scattered over the swollen ends. The medusa-bud is larger 
than the others and is lower on the tube. It liberates a swimming-bell, 
which is called Sarsia. (Plate XLI.) 
Sarsia 
S. mirabilis. This medusa of Coryne is from one 
quarter to three quarters of an inch in diameter when 
full-grown. Its umbrella is nearly hemispherical, and 
from the center hangs a manubrium. From the margin 
of the umbrella hang four very long tentacles. The shape 
of its body and the length of its tentacles and proboscis 
are constantly changing as it moves in the water. These 
little meduse are very plentiful in the spring and summer, 
and swim rapidly in all directions near the surface of 
the water. 
Genus Tubutlaria 
T. Couthouyi. This species is found in the same places 
as Parypha crocea. The stem is three to six inches long, 
and is inclosed in a horny sheath, which is more or less 
ringed or jointed, or it may be smooth throughout. The 
head, when the tentacles are expanded, measures one and 
a half inches in diameter. It hasa proboscis covered with 
tentacles, disposed in series, which grow successively 
shorter, the last being merely papille. The medusa-buds 
hang in clusters between the outer tentacles and the pro- 
boscis. The animal grows in bunches of five to ten tubes, 
which spring froma creeping, tangled stem. (Plate XLT.) 
\ Genus Parypha 
Sarsia, the free P. crocea. This is one of the most beautiful of the tubu- 
medusa of Corye. larians, It has a large, drooping head on a stem three to 
