PLATE 39 



Fig. 9. Colony of Macroclinum pellucidum with zooids seen through trans- 

 parent test. X 6. 



Fig. 10. Small portion of a colony of Botryllus tuberatus showing a single 

 system of zooids, two tuberlike masses of ectodermal ampullae, c.a., and ecto- 

 dermal vessels. X 8. 



Fig. 11. Colony of Didemnum carnulentum. X 2. 



Fig. 12. A single system of Botryllus ttiberatus, showing character of the 

 common cloacal orifice. The lower lip of atrial siphon extends beyond edge of 

 common orifice. X 8. 



Fig. 13. Colony of Glossophoruni planum. Natural size. 



Fig. 14. Three zooids of Metandrocarpa mirliaeheiii showing trails of test 

 and ectodermal processes. 



[496] 



