PLATE XII. 
Colella thomsoni, n. sp. 
Fig. 1. The anterior end of an Ascidiozooid, seen from the interior ; magnified (S., 1 inch). 
Fig. 2. The anterior end of an Ascidiozooid, showing the branchial aperture, tentacles, 
&c., seen from the interior; magnified (S., 1 inch). 
Fig. 3. The anterior end of an Ascidiozooid, seen from the exterior ; magnified (S., 1 inch). 
Fig. 4. The alimentary canal; magnified (S., 1 inch, enlarged). 
Fig. 5. A transverse section across the abdomen of the Ascidiozooid ; magnified (S., 1 
inch, enlarged). 
Fig. 6. The abdomen of an Ascidiozooid, showing the alimentary canal and reproductive 
organs ; magnified (S., 1 inch, enlarged). 
Fig. 7. The male reproductive system of an Ascidiozooid ; magnified (S., 1 inch, enlarged). 
Fig. 8. A transverse section across the abdomen of a young Ascidiozooid, showing the 
ovary; magnified (S., 1 inch). 
