82 ASCIDIANS CHAP. 
2. The PARIETAL, or “ peribranchial ” type—seen in the Holo- 
somata, typically in the Botrylldae. 
The remarkable process of gemmation seen in the families 
Didemnidae and Diplosomatidae, where the bud arises from at least 
two rudiments, the one stolonial or epicardiac in origin, and the 
Fic. 46.—A, Ascidiozooid from a Bot- 
ryllid colony ; B, ascidiozooid from 
a Distomid colony ; C. ascidiozooid PRaCP- 
from a  Polyclinid colony. a, 
Anus; at, atrial aperture; at.J, B 
atrial languet ; br, branchial aper- 
ture ; cl, cloaca ; d.l, dorsal languet ; ec, ectoderm ; 
end, endostyle, ep.c, epicardiac tube ; g/, intestinal m 
gland; h, heart; 7, intestine; 2.g, nerve-ganglion; 2 
oes, oesophagus ; ov, Ovary ; p.c, pericardium ; 7, 
rectum ; sg, stigmata of branchial sac ; sp, spermatic sacs ; 
sph, sphincter; st, stomach; ¢, tentacle; ¢.4, terminal C 
ampullae of vessels in test; v, colonial vessels; v.app, 
“vascular appendage ” (stolon). 
woqav-Lsod 
other formed by one or more oesophageal or intestinal outgrowths, 
has been called “entero-epicardiac,” but it may probabiy be re- 
garded as a modification of the stolonial type. 
The marked differences in the appearance of the colonies of 
Compound Ascidians is largely due to the methods of budding ; 
and even in those of the stolonial type, where the budding is 
practically the same in essential nature, the results may be very 
different in superficial appearance, according as the buds are 
