PLATE XVII. 



PAGE 



Fig. 26 a. Section from Crioceras percostatus. 77 



Fig. 27. Bactjlites Chicoensis. Natural size. 80 

 a. Section. 



Fig. 28. Bactjlites, Sp. indet. Natural size. 81 



Fig. 31. Attjria Mathewsonii. Natural size. 69 



