PLATEXViI- 
Transverse sections of Echinoid Radioles. 
Pag. Pag, 
452. «Cidaris» trigona, from St. Cassian (Brit. | 453. «Cidaris» linearis, from St. Cassian (Brit. 
Mus., E 10101); the flattened face is upper- | Mus., E 10102); the position of the axis 
most; the axis of the radiole lies at the | is marked by a cross; X 60 diam. . 227 
lower right-hand corner of the figure; x 30 . 
Dic eM Eee sy es yar 20 
All figures were drawn from the sections by G. T. Gwitt!am, under the Author’s direction, at a magnification 
of 80 and 40 diameters, respectively, and were reduced by photography to the present scale. 
