CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA 33 
for when the ciliated epithelium is stretched through the contraction of 
the underlying muscles the cilia are stopped, but if the muscles be re- 
laxed, as by magnesium, the surface tension is reduced and the cilia 
are free to beat. 
Fic. 10.—Mnemiopsis mcecradyi, from life by the author. Natural size. Let- 
tering as in fig.g. Port Royal, Jamaica, May 1, grr. 
Mnemiopsis gardeni L. Agassiz. (Fig. 47, plate 8.) 
Munemiopsis gardeni, Acassiz, L., 1860, Cont. Nat. Hist. U.S., vol. 3, pp. 269, 290, 
figs. 95, 96.—Acassiz, A., 1865, North Amer. Acal., p. 20, figs. 20, 21. —Cutn, 
C., 1898, Ctenophoren der Plankton-Exped., p. 25. 
(?) Bolina littoralis, McCravy, 1859, Proc. Elliott Soc., Charleston, vol. 1, p. 254, 
plate 14, figs. 1-14 (development). 
This is a small species, being only 35 to 4o mm. long when mature. 
The oral lobes are of very small size, being only one-fifth to one-sixth as 
long as the body of the animal. The auricles, however, are well developed, 
being relatively about as long as in M, leidyi and about one-third as long 
as the entire body of the animal. There is considerable lateral compres- 
sion, the sagittal diameter being about 2.5 times as great as the tentacular. 
The 4 deep lateral furrows extend from the level of the mouth about 
three-quarters the distance up the sides of the body. They are not as 
