No. 8.— Studies of the Jelly-fishes of Narragansett Bay. By 
J. WALTER FEWKES. 
Tun following pages contain an account of certain new 4Acalephe col- 
lected by me during three summers’ work at Newport, R. L,* with notes, 
anatomical and embryological, on those which have been previously 
known. A few jelly-fishes are also described from drawings and notes 
mado by Mr. Alexander Agassiz, since 1865, at Newport and Naushon. 
These are mentioned in the appropriate places under the respective 
meduse. 
HYDROIDA. 
Sarsia mirabilis, Acassiz. 
Plate III. Figs. 11, 12. 
S. mirabilis is rarely found in Narragansett Bay. During the summer 
months which were spent in Newport, only two specimens of this jelly-fish 
were found. If one contrasts this rarity of the medusa south of Cape Cod 
with its abundance at times in the waters of Massachusetts Bay, the conclusion 
seems evident that the specimens which were captured in the former locality 
were stragglers, and do not strictly belong to the fauna of Narragansett Bay. 
A portion of the base of the tentacle of S. mirabilis is specialized into a spher- 
ical body, which projects downwards as the jelly-fish swims in the water, hang- 
ing below the margin of the bell. 
The walls of this spherical enlargement at the base of the tentacle are formed 
of two layers, and enclose a number of cellular bodies, which resemble indis- 
tinctly lasso cells. They appear to have some special function, and are not 
found in other genera of our coast closely related to Sarsia. Covering the sur- 
face of the walls in which they are contained, there are many small, bright red 
pigment dots. The true eye-spot (ocellus) is black, and is mounted ona pa- 
pilla, which rises on the upper and external side of the base of the tentacle. 
The spherical enlargement previously mentioned is on the under and opposite 
side of the base of the tentacle. A figure to illustrate the general appearance 
of the tentacular bulb, with the two structures, ocellus and problematical sense 
organ (spherical body with contained cells), is given, with an enlarged view of 
part of the latter structure, in Plate IIT. figs. 11, 12. 
* Tam indebted to Mr. Agassiz for facilities to carry on this work in his private 
laboratory, at Newport, R. I. 
VOL. VIIT.— NO. 8. 
