gO TUNICATA—SALPIANS CHAP. 
the posterior end of the branchial sac. Hermaphrodite repro- 
ductive organs le ventrally near the intestine. 
This group is clearly distinguished from the second sub-order, 
the Hemimyaria, by the condition of the muscle-bands and of the 
branchial sac, and by the life-history. The muscle-bands are 
complete rings (except in Anchinia), while in the Hemimyaria 
they are always more or less incomplete. The branchial sac 
in the Cyclomyaria is a distinct cavity, and communicates with 
the peribranchial cavity only by small slits or stigmata. The 
life-history is also very characteristic, as the sexual generation in 
the Cyclomyaria is always polymorphic, while in the Hemimyaria 
it consists of one form only. 
Structure of Doliolum.—tThe single family DoLIoLipDAx in- 
cludes three genera, Doliolum, Quoy and Gaimard, Dolchinia, 
Korotneff, and Anchinia, Eschseholtz. Doliolum, of which about 
a dozen species 
are known, from 
various seas, has 
a cask - shaped 
body (Fig. 59), 
usually from 1 
to. 2... Chae 
length. The ter- 
minal branchial 
and atrial aper- 
tures are lobed, 
Fig. 59.—Sexual generation of Doliolwm tritonis, Herdman, Pane lio. 
from left side. x10. at, Atrial aperture; at./, atrial an. € 1obes are 
lobes ; at.m, wall of atrium ; br, branchial aperture ; 67./, provided with 
branchial lobes ; 67.s, branchial sac ; d.t, dorsal tubercle ; 
end, endostyle ; h, heart ; 7, intestine ; m, mantle ; m'-m8, S€NSe-Organs. The 
circular muscle-bands ; , nerve ; 7.g, nerve-ganglion ; 0v, test is a thin but 
ovary ; p.br, peribranchial cavity ; p.p, peripharyngeal 
bands ; sg, stigmata ; s.g/, neural gland ; s.0, sense-organ ; tough transparent 
st, stomach; ¢, test; tes, testis; z, prebranchial zone. layer and con- 
(After Herdman.) J 
tains no “ test” 
cells. It is merely a cuticle covering the surface of the squamous 
ectoderm. The body-wall has eight or nine circular muscle-bands 
surrounding the body. The most anterior and posterior of these 
form the branchial and atrial sphincters. The wide branchial and 
atrial apertures lead respectively into branchial and peribranchial 
cavities separated by the posterior and postero-lateral walls of 
the branchial sac which are pierced by a considerable number of 
