PLATE V. 



PA1JE 



Pig. 1. Helodus compressus. Enlarged to two diameters 78 Yt*~>^*yv** ** % 



Fig. 2. Helodus folitus. Posterior face 79 r^oX-^'lC 



b 

 Pig. 3, 3 a. Helodus oibbosus. Posterior face and profile section 79 '' 



Fig. 4, 4 a. Helodus placenta. Upper and posterior surfaces 80 %*$***& *|V^ J*-^ 



Fig. 5, 5 <?, 5 b. Helodtts limax. Top, side and end views 80 |i*»&<-\V- X w«i. ' 



Fig. 6, 6«, 6 b. Helodus denticulatus. Side and top views, and profile section 81 mV/w v H. 



f 

 Fig. 7, 7 a. Helodtts orenulatub. Upper and Under surfaces 82 " 



Fig. 8, 8", 8 b. Helodus undulatus. Top and side views, and section 82 U 



Fig. 9, 9", 9 4. Helodus angulatus. Top, side and end views 83 IlW^^WI 



10 to 15 a. Teeth of different sizes and forms. 



Fig. 18, lfi a. Helodus suloatus. Top and side views of small tooth 83 ^ t * ,, ' 1 * % ^ 



Fig. 17, 17 a. Chomatodus ? oostatus. Upper surface and section 85 '* 



Fig. 18,18 ', 18''. Chomatodus elegans. Side and top views, and profile section 86 



