PLATE XVIII. 



FIG. 1. Acrotrcta sipo. Section of the ventral valve, showing the siphon. See p. 185. 



FIG. 2. Acrotrcta sipo. Interior of the dorsal valve, showing the median septum. Both 

 Mag. f , and from Assise C c 2 , McLeod brook, Boisdale, N. S. See p. 185. 



FIG. 3. Bellcrophon insulaz Sinistral side Mag. f. From Assize C Be 2 , McLean 

 brook, Boisdale, N. S. See p. 217. 



FIG. 4. Bellerophon Brctonensisa Dextral side ; I Broken valve, showing interior, 

 &c. Both natural size ; c Dorsum, showing angle of the growth of lines. 

 Mag. f ; d Part of surface of body wall. Mag. f All from Assise C 3c 2 . 

 McLeod brook, Boisdale, N. S. See p. 218. 



FIG. 5. Bellerophon semisculptus Showing the outer whorl Mag. \. From Assise, 

 C 3c 2 , McLeod brook, Boisdale, N. S. See p. 219. 



FIG. 6. Urotheca, sp. Tube, showing larval part and living chamber. From Assise, 

 C 3c 2 , McLeod brook, Boisdale, N. S. See p. 183. 



FIG. 7. Parabolinclla (?) quadrata Middle piece of head-shield. Natural size. From 

 Assise C 3c 2 , McLeod brook, Boisdale, N. S. See p. 225. 



FIG. 8. Triarthrus Belli Middle piece of the headshield, right side and occipital ring 

 restored. Mag. f. From Assise C 3c 2 , at McLeod brook, Boisdale, N. S. 

 See p. 230. 



FIG. 9. Angelina ? sp. Larval cephalic shield. Mag. f. From Assise, C 3c 2 , McLeod 

 brook, Boisdale, N. S. See p. 232. 



FIG. 10. Asaphellus Homfrayi, var. a Adult, broad form, partly restored; b Middle 

 piece of the headshield of the narrow form ; c The hypostome. All natural 

 size ; d Early larval form. Mag. ty ; e A later larval form Mag. . All 

 from Assise, C 3c 2 , at McLeod brook, Boisdale, N. S. See p. 232. 



FIG. 11. Asaphellus (?) planus. Adult Natural size ; the pygidium enlarged from 

 another example supposed to be of this species. From Assise C 3c 2 , at Mc- 

 Leod brook, Boisdale, N. S. See p. 237. 



