212 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



3. The alimentary canal, X 20. 



4. Molgula holtiana, from left side, nat. size. 



5. Body with test removed, from left side, nat. size. 



6. Same from right side, nat. size. 



7. Part of branchial sac, X 50. 



8. Dorsal tubercle, tentacles, &c, X 50. 



Plate X. 

 Ascidiella aspersa, var. pustulosa. 

 Fig. 1. Abnormal small tentacle, X 50. 



2. Abnormal caecum from intestine, slightly enlarged. 

 3 and 4. Abnormal deficiencies in wall of branchial 



sac, nat. size. 

 5 and 6. Large holes at posterior end of test, nat. size. 

 7. Posterior end of body of specimen drawn in fig. 6, 



showing branched vessels, nat. size. 

 8 — 10. Some of the twigs of these vessels, X 50. 



