PLATE XLI. 



FIGS. 



1-3. Styela mamillaris (Graertn.). (p. 106) Test and 

 mantle laid open : about twice natural size. 1. 

 Exposing 1 outer surface of branchial sac. 2. 

 Branchial sac partly removed, exposing its inner 

 surface, also anus, reproductive organs, etc. 3. 

 Branchial sac wholly removed, exposing digestive 

 and reproductive organs. 



4 and 5. Styela coriacea A. & H. (p. 109) Test and mantle 

 laid open : about twice natural size. 4. Exposing 

 branchial sac. 5. Branchial sac removed, ex- 

 posing digestive and reproductive organs, v. h. 

 " vessel from heart.' 



