156 MARINE INVERTEBRATES 
ORDER CYDIPPIDA 
Genus Plewrobrachia 
P. rhododactyla. 
A transparent spher- 
ical body, one inch to 
one and a half inches 
in diameter, with 
eight combs or plates 
of flat cilia extending 
from pole to pole. 
At one pole is the 
mouth, like a slit, at 
the other a small area 
in the center of which 
isan eye-spot. From 
the body hang two 
tentacles, half a yard 
or more in length, 
fringed with cilia. 
The tentacles are 
very contractile and 
can be rolled up or 
< expanded with great 
Pleurobrachia rhododactyla, in motion. rapidity 3 they take 
graceful curves as the 
animal moves rapidly through the water. Plewrobrachia has a pink tint, 
and prismatic colors play over it from the vibrating cilia. Itisa beautiful 
and interesting creature to watch. Found 
along the shores of Massachusetts and Maine. 
o 
Ara? 
: & 
aff | TR 
ORDER LOBATA v #-g_{\|\ fe Sr 
Genus Bolina - 
B. alata. Slightly oval in form; lower a 
part of the body divided into two large lobes B \~6 
which hang below the mouth. Four of the *\\ \ f. 
swimming-plates are shorter than the other ¢\ LAN s 
four and terminate in curious processes or : ar (eo 
short appendages called auricles. Bolina is . 
about two inches in length, and is very Pi oe ep Re ee ae 
10, peck ; m, mouth; 1, au- 
delicate, transparent, and phosphorescent. ricles ; v, digestive cavity ; 9, h, short 
Its contractile power enables it to vary in rows of flappers; a, f, long rows of 
outline to a considerable extent. It has a Toppers: b% t.% tubes winding in 
e larger lobes; i, base of gullet. 
slow undulating motion, and sometimes ayouthalf natural size. 
carries its lobes uppermost and open. Usu- 
ally found associated with Pleurobrachia from Massachusetts northward. 
. septentrionalis. Found on the northern Pacific coast. 
B, vitrea. A species found in Florida. 
