ON THE DIPLOCHORDA. 727 



7. Masterman, a. T. — " On the Diploclioida," part ii, ' Q,. J. M. S.,' Aug. 



1897. 



8. „ "On the Notochord of Cephalodiscus," ' Zool 



Anz.,' No. 545, 1897. 



9. „ " On the Origin of Vertebrate Notochord and Pha 



rjngeal Clefts," ' Hep. Brit. Assoc.,' Sept., 1898 



10. ,, "On Further Auat. and Budding Processes ol 



Cephalodiscus," 'Trans. Hoy, Soc. Edinb., 

 vol. xxxix, pt. iii, No. 17. 



11. ,, "On the Diplochorda," part iii, ' Q,. J. M. S., 



vol. xliii, pt. ii. 



DESCRIPTION OF PLATES 32 & 33, 



Illustrating Mr. A. T. Masterinaii's paper " On the 

 Diplochorda.^' 



Figs, 1 — 5. — Selected sections (1, 3, 5, 7, 15) from a longitudinal sagittal 

 series through Cephalodiscus dodecalophus (Zeiss, obj. 7, eyep. 1). 



Figs. 6 — 8.— Selected sections (1, 4, 6) from a transverse series through 

 Cephalodiscus dodecaloplms (Zeiss, obj. 7, eyep. 1). 



Fig. 9. — A semi-diagrammatic right half of a polyp. 



