118 
OTTO C. GLASER 
In addition to the rhinophores (fig. 1), with their parallel rings, 
and the mobile foot-tentacles, sensitive to touch, eolids possess 
numerous dorsal appendages, or cerata. These structures, often 
banded distally, and tipped with blue, purple, grey, or white, 
occur in clusters symmetrically distributed on the sides of the 
body. When, as is frequently true, the cerata are very abundant, 
their distribution seems to be uniform; nevertheless each ceras 
belongs to a particular group that radiates from an enlargement 
on the side of the body. These swellings are regions of prolifer- 
Fig. 1 Typical eolid, showing rhinophores with parallel ring-like swellings; 
foot-tentacles, and cerata of various sizes radiating in groups from lateral enlarge- 
ments. 
ation and from them arise new appendages in such manner that 
the oldest in each collection is nearest the sagittal axis of the 
animal. 
A median section through such a ceras (fig. 2), shows an ecto- 
dermal covering (ECT), indistinct in cell-boundaries, and rich in 
mucous glands. Inside this are bundles of longitudinal and cir- 
cular muscles (MUSC), enclosing a more or less capacious duct 
whose distal pore (CNDP), completes a passageway from the 
lumen of the liver to the outside. This duct, lined proximally 
with hepatic cells, then with cihated epithelium, leads distally 
into a cnidophore filled partially or completely with cells or cysts 
-containing nettles. The basal entrance into the cnidophore 
is guarded by a sphincter (SPH). 
