COMPOUND ASCIDIA. 173 



Plate XL. Fig. 6. Botryllus of yellow colour investing an Ascidia rustica. 



7. System of the specimen, Plate XLI. fig. 2. 



8. Portion of the specimen, Plate XLI. figs. 3, 4, consisting of 



a system formed by ampullate ascidke, J, around a central 

 orifice, a, enlarged. 



9. Ascidire of the specimen, Plate XLI. figs. 3, 4, with indistinct 



orifices. 

 10. System of the specimen, Plate XLI. fig. 5. 



All the figures of this Plate, except figs. 1, 2, 4, 6, are en- 

 larged. 



Plate XLI. Fig. 1. Botryllus with dark orange systems. 



2. Botryllus of umber colour, with systems of from four to 



eleven ascidise, one of which is represented in Plate XL. 

 fig. 7. 



3. Botryllus with indefinite systems on one side. 



4. Opposite side of fig. 3, with definite systems. 



5. Botryllus covered by between sixty and seventy systems. 



