MUSEUM OF COMPARATIVE ZOOLOGY. 165 
The development of the egg of Turritopsis is unknown. Eggs were ob- 
served to be dropped in August. The younger stages of the medusa are 
characterized by the tenuity of the bell walls, and the short tentacles, which 
are sometimes carried stiffly thrown back along the side of the bell or tightly 
coiled round the tentacular bulbs. 
ไว เมน ห อ ห ล strangulata, McCrapy. 
Plate IV. Fig. 5. 
Two species of Dipurena, D. strangulata and D. cervicata, were described 
from Charleston Harbor by McCrady, who founded the genus. A third 
species, D. comica, is described from Naushon, Vineyard Sound, by MES 
Agassiz. 
A single specimen of D. strangulata was captured by the author at Newport, 
in September. The bell is half-egg-shaped, with the minor axis greater than 
the height. It is very transparent, colorless, and has a smooth surface. Ra- 
dial tubes four, resembling fine lines on the bell, and simple in profile, Pro- 
boscis long, slender, extending when protruded far outside the bell opening, 
and with ovaries so distended with eggs that it can with great difficulty be 
withdrawn into the bell cavity. At the point on the inner surface of the bell 
from which it is suspended, there is an enlargement in the neck of the probos- 
cis into a kind of bulb, which has bright red contents. The function of this 
bulb is not known. A similar structure, reduced in size, is found in many 
other medusæ, as in Sarsia mirabilis, Ectopleura ochracea, and some others. 
The sexual organs are divided into two parts, or arranged in two packets on 
the proboseis, separated. by an interval from each other. "The upper of these 
is placed about midway between the bulb already mentioned and the mouth 
or the distal end of the proboscis. This division of the sexual organ is a 
simple oblong body of uniform size throughout. Through the external walls 
the motion of the chymiferous fluid within the proboscis can be well seen. 
The enlargement around the cavity of the proboscis is filled with ova. The 
upper portion of the surface is covered with minute warts, the lower bears 
patches of bright crimson color. The whole has a greenish color throughout. 
The lower of the two divisions into which the sexual glands are divided is 
larger than the former, and has a slight constriction midway in its length. In 
it also, as in the former, the walls of the stomach may be easily seen, sur- 
rounded by the peripherally placed eggs. Like the lobe already mentioned, 
it too has patches of crimson color in its lower half, and the surface is set 
with lasso-cells (?). The mouth is simple, and destitute of tentacles or knob- 
like appendages. The tentacles are short, stiff, solid, or with a very small 
central cavity, and are generally carried at an angle to the bell. They are four 
in number. The tentacular bulb is large, spherical, with green pigment, and 
a single small black ocellus externally placed on a slight projection from the 
bulb. The distal end of the tentacle is a dumb-bell shaped organ, which is 
