154 BULLETIN OF THE 
do not show this protuberance, for the reason that the specimens which he 
drew had the proboscis more or less protruded outside the bell cavity. The 
external surface of the bell in the adult is smooth, and in the young is crossed 
by eight meridional lines of cells, two of which arise from each tentacle 
and extend to the pole of the bell, where all have a common junction. The 
radial tubes are narrow, thread-like, and not “wide,” as McCrady says. They 
are four in number. The proboscis is without peduncle. McCrady gives a 
long description of what he calls a cellularupper portion of the proboscis, which 
resembles a peduncle as found in some other medusæ. This cellular structure is 
in reality the inverted upper part of the bell cavity of a Turritopsis in which the 
proboscis has been extended outside the bell opening. The bell of this genus 
is often reversed, so that the whole of the proboscis with attached ovaries is 
pushed out exterior to the bell, just as takes place in other genera, as Hucope 
and Obelia. As a result of this protuberance of the proboscis, the upper part of 
the bell is infolded and pressed into a “ cellular body,” like a peduncle. In 
normal positions of the medusa the proboscis has no such peduncle. 
The ovaries are large, and arranged in four lobes, which cover the whole up- 
per part of the proboscis. Their color is orange. Of oral tentacles there are 
four, each one of which is subdivided into two parts at the extremity, and cov- 
ered with very peculiar knobs, mounted on short retractile, thread-like pedicles. 
These knobs, as McCrady pointed out, give to the extremity of the oral ten- 
tacle a “frosted appearance." They are characteristic in their form of the 
genus Turritopsis. A few of the same kind of pedunculated cells are found 
near the first bifurcation of the oral tentacles, but the most of them are con- 
fined to their extremities. The tentacles are numerous, with a length twice 
the height of the bell, hollow, flexible, and clavate at their extremities. When 
at rest they are coiled around the base, not unlike the position assumed by the 
tentacles of Trachynema digitale, A. Ag. The number of tentacles in the oldest 
specimen is thirty. The tentacular bulbs are so closely crowded together that 
intermediate sections of the margin of the bell cannot be seen, or are so very 
small that the tentacular bulbs appear to touch each other. 
Otocysts wanting. 
Locality, Newport, R. T. 
I have not noticed in the jelly-fish the zigzag motion which is mentioned by 
McCrady, but the movement was always direct, consisting of several succes- 
sive rapid contractions of the bell and veil, and then a pause followed at a 
short interval by similar exertions. McCrady says Turritopsis is gregarious. 
It is found accompanied by large numbers of the same kind, but cannot be 
said to be more gregarious than many other jelly-fishes. Accumulations of 
many in one place are due to tide eddies. 
The younger stages in the growth of the medusa have been well figured by 
Mr. Agassiz. A few intermediate stages are given by me to fill up the gaps in 
the developmental history (Plate IV. figs. 4, 6, 7, 9, 10). Fig. 6 is a magnified. 
view of one of the peculiar knobs found principally on the extremities of the 
oral tentacles, and characteristic of the genus. 
