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Proceedings of the Royal Society 
and possibly Rhopalcea , as the family ClavelinidvE, and place them 
next to tbe AscidiadyE in the Ascidice simplices. 
CLAVELINIDiE. 
Branchial sac having 
internal longitudi- 
nal bars. 
Branchial sac having 
no internal longi- 
tudinal bars. 
1 
1 
Internal longitu- 
Internal lon- 
dinal bars bear- 
gitudinal 
ing papillae. 
bars having 
1 
no papillae. 
I 
1 
Rhopalcea. 
1 
Ecteinascidia. 
Test very thick. Test thin, at 
least on 
thorax. 
Branchial sac 
not papil- 
lated. 
Clavelina. 
j 
Branchial sac 
papillated. 
Perophorct. 
E. crassa. 
Tentacles few, Tentacles 
all one length. about 80, 
of three 
lengths. 
E. fusca. E. turbinata. 
Horizontal mem- 
branes round 
branchial sac 
narrow. 
C. oblonga. 
Horizontal mem- 
branes round 
branchial sac 
very wide. 
C. enormis. 
Ecteinascidia , n. gen. 
External appearance. — Shape oblong, tapering posteriorly. 
Branchial sac having internal longitudinal bars, but no papillae. 
Dorsal lamina reduced to languets. 
Tentacles simple. 
Viscera extending beyond branchial sac posteriorly. 
This genus is formed for the reception of three species which 
seem to be intermediate in their characters between Ciona and 
Clavelina , and, except in one point, resemble Philippi’s Rhopalcea 
more than any hitherto described form. 
