ASCIDIA. Q5 
EXPLANATION OF PLATES. 
Ppxew & 
Large specimen of Ascidia mentula, from the right side, 
natural size, from life. 
Length 11°5 cm. 
Breadth 6 cm. 
Thickness 3 cm. 
A, shows the sensory edge of the branchial aperture 
with lobes and coloured lines (the “ ocelli’’), enlarged. 
rar ih: 
Reference Letters in Plates IT., ITI., and IV. 
a. anus. 
At. atrial aperture. 
at.l. atrial lobe. 
bl.c. bladder cell. 
bl.s. blood sinus. 
Br. branchial aperture. 
br.car. branchio-cardiac vessel. 
br.ao. branchial (ventral) vessel. 
Br.s. branchial sac. 
br.visc. branchio-visceral vessel. 
card.visc. cardio-visceral vessel. 
c.c. common cloaca. 
c.d. connecting duct. 
cl. cloaca. 
con. connective. 
c.t.c. connective tissue cell. 
d.ao. dorsal vessel. 
d.bl.s. dorsal blood sinus. 
d.l. dorsal lamina. 
d.n. dorsal nerve cord. 
d.t. dorsal tubercle. 
ec. ectoderm. 
en. endoderm. 
end. endostyle. 
ep.c. epicardial tube. 
g.d. genital duets. 
gl. pyloric gland. 
gl.d. duct of neural gland. 
gon. gonads. 
h. heart. 
h.m. horizontal membrane. 
hyp. hypophysial (neural) gland 
hyp.d. hypophysial duct. 
1.2’. 1otestine. 
z.l. internal longitudinal bars. 
/.v. interstigmatic vessels. 
m. body-wall, or mantle. 
_m.b. muscle bands. 
mes.c. mesoblast cell. 
m.f. muscle fibres. 
2. Nerves. 
N.g. nerve ganglion. 
n.gl. neural gland. 
es. cesophagus. 
ov. ovary. 
p.br. peribranchial cavity. 
p.br.z. prebranchial zone, 
.c. pericardium, 
p.p'. papille. 
pp.b. peripharyngeal bands. 
