ECTEINASCIDIA AND THE CLAVELINID2E. 163 



Plate VI. 

 Ecteinascidia thurstoni, n. sp. 

 Fig. 1. The entire colony, natural size. 

 Fig. 2. An ascidiozooid, slightly enlarged. 

 Fig. 3. Another ascidiozooid, nat. size. 

 Fig. 4. Part of the mantle showing the transverse 



muscles, X 50. 

 Fig. 5. Part of the mantle showing the engorged blood 



spaces, X 50. 

 Fig. 6. Part of the branchial sac from the inside, X 50. 

 Fig. 7. Part of the dorsal edge of the branchial sac 



showing the languets, X 50. 

 Fig. 8. The dorsal tubercle, X 50. 

 Fig. 9. The alimentary canal and genital organs, X 10. 



Plate VII. 

 Ecteinascidia moorei, n. sp. 

 Fig. 1. The entire colony, natural size. 

 Fig. 2. A single ascidiozooid, slightly enlarged. 

 Fig. 3. The atrial aperture from the interior to show the 



lobes and the musculature, X 50. 

 Fig. 4. Part of the branchial sac from the inside, X 50. 

 Fig. 5. Part of the dorsal edge of the branchial sac, 



showing the languets, X 50. 

 Fig. 6. The dorsal tubercle, X 50. 



Fig. 7. The alimentary canal and genital organs, X 10. 

 Fig. 8. Some of the tentacles, X 50. They seem to be 



exactly alike in the two species, E. thurstoni 



and E. moorei 



