GEROULD: CAUDINA. 
73 
EXPLANATION OF PLATES. 
All the figures except 46, 67, 78, and 80 were made with the aid of a camera 
lucida, and all except 34-37, 53, 86, and 101 are from Caudina arenata Gould. 
Figures 34-37 are from C. arenata var. armata Theel. 
Figures 53, 86, and 101 are from Cucumaria frondosa. 
Abbreviations. 
amp. 
Ampulla of tentacle. 
en'th. 
Endothelium. 
aim. n. 
Nerve ring. 
e'th. 
Epithelium. 
aq. crc. 
Circular water canal. 
e'th. hue. 
Epithelium of the buccal 
aq. r. 
Radial water canal. 
region. 
aq. r.' 
Median-ventral radial 
e'th. ex. 
External epithelium. 
water canal. 
e'th. ex. oa. 
External epithelium of 
aq. ta. 
Tentacular branch of ra¬ 
the ovary. 
dial water canal. 
e'th. i. 
Internal epithelium. 
atj. ta.' 
Tentacular branch of ra¬ 
fbr. sst. 
Supporting fibers of 
dial water canal to me¬ 
nerve bands. 
dian-ventral tentacle. 
gl. tbl. 
Tubular gland cell. 
can. lap. 
Stone canal. 
h'pn. r. 
Hyponeural canal. 
clc. 
Cloaca. 
lac. oa. 
Lacunar blood vessel of 
cl. fol. 
Follicular cell. 
the ovary. 
cl. qn. 
Ganglionic cell. 
mad. 
Madreporic body. 
Cl . S/18. 
Sensory cell of epithe¬ 
m'py. 
Micropyle. 
lium. 
ms'ent. d. 
Dorsal mesentery. 
cl. sst. 
Supporting cell of epi¬ 
mu. 
Muscle fibers. 
thelium. 
mu. crc. 
Circular muscle fibers. 
cl. vag. 
Wandering cell in pha¬ 
mu. Ig. 
Longitudinal muscle fi¬ 
rynx. 
bers. 
cp. sph. 
Spheruliferous wander¬ 
mu. IgJ 
Longitudinal muscles in 
ing corpuscle. 
the wall between aq. r. 
cp. sph.' 
Spheruliferous corpuscle 
and h'pn. r. (Plate 4), 
with finer spherules 
and longitudinal mus¬ 
than cp. sph. 
cle fibers of rudimen¬ 
da. 
Cuticula. 
tary ambulacral foot 
dt. gen. 
Genital duct. 
(Plate 6). 
e'n. crc. 
Circular epineural canal. 
mu. Ig. ta. 
Longitudinal muscles of 
e*n. r. 
Radial epineural canal. 
tentacles. 
