CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA 25 
Bolina elegans Mertens, 1833 (Mém. Acad. Sci. St. Pétersbourg, 
Sci. Math. Phys. et Nat., sér. 6, tome 2, p. 513, Taf. 6, fign. 1-4), from 
the South Seas, is also pink in general color, but the upper parts of the 
body are covered with numerous small papilla and these are absent in 
the Florida species. B. hydatina of Chun is evidently the immature B. 
vitrea from the Mediterranean. 
Fic. 7.—Bolinopsis vitrea. Adult, 1.25 times natural size. Show- 
ing oral lobe expanded, and canals. Tortugas, Florida, June, 
1910. From life, by the author. 
A solution of 0.6 molecular sodium chloride inhibits and soon stops 
the movements of the cilia of B. vitrea, but solutions of o.4 molecular 
magnesium chloride or molecular magnesium sulphate which are isotonic 
with the sodium chloride of sea-water have an opposite effect, for they 
produce an abnormally rapid movement of the cilia, each comb beating 
independently, and the coérdination of the rows of combs being destroyed. 
In solutions containing potassium in weak concentration the combs stop 
momentarily and then resume their movement. 
This converse relation between ciliary and muscular movement may 
be explained in the following manner: When the muscles contract, the 
