418 ARTHUR T. MASTERMAN. 



Figs. 51 — 54.— Lateral views of Phoronis australis, natural size. 

 Fig. 55. — Longitudinal section through body-wall of trunk region ot 

 Phoronis Buskii. 

 Fig. 56. — Transverse section througli nerve-ring of P. Buskii. 

 Fig. 57. — Isolated elements from Fig. 58. 

 Fig. 58. — Longitudinal section through epistome of P. Buskii. 

 Fig. 59. — Transverse section of lophophore of P. Buskii. 



PLATE 21. 



Fig. 60. — Diagram of transverse section through lopliO|iliore of P. 

 buskii, showing currents. 



Fig. 61. — Longitudinal sagittal section through lophophore of P. buskii, 

 showing currents. The section is supposed to pass through A. in fig. 60, 

 but the coil of end coil in fig. 60 should be twisted a little more, so as to be 

 cut once more by the line. (Cf. fig. 59.) 



Fig. 62. — Median sagittal section through lophophore of P. Buskii, 

 showing currents. The section is su[)|)0sed to pass through B. in fi^'. 60. 



