PLATE VIII. 



Upper OrJovician Ccpltalopoda: — MaclnaJcou Limestone. 



Drairinrjs by K. C. Lin (fiJjfeM) 



Fig. 1. Aiiinoceras coulingi Grabau p. 82 



A natural section upon the rock surface, somewhat weathered, and showing the 

 siphuucle, irregular septa, and filling of camerse by stereoplasm. Natural size. 

 Machiakou limestone, Hsi-Hsien, Honan. (Cotype, A. C. Taun coll., G. S. Oh. 

 Cat. No. 4) . 



Fig. 2. 'Actinoceras coulingi Grabau p. 82 



Polished section of a characteristic specimen, showing the siphuncle and nature and 

 extent of filling of caraerse. Natural size. Machiakou limestone, Ma-Chia-Kou, 

 Chihli. (Cotype, H. C. T'an coll. G. S. Ch. Cat, No. 27). 



Fig. 3. Actiiioccrcifi snanpanoides Grabau p. 84 



3a. Somewhat oblique polished section showing depth of camerse and their filling, and, 

 in the lower part, the siphuncle. The rate of tapering appears abnormally great 

 owing to the oblique direction of the section. Natural size. 



3b. Transverse section of upper end. Machiakou limestone, Tai-An, Shantung. 

 (Cotype, G. S. Ch. Cat. No. r,3). 



Fig. 4. Aclinocera-1 snanpanoides (irabau p. S4 



4a. Polished section, showing tlie characteristic siphuncle, rate of tapering of shell, and 



filling of camerfe. 

 4b. Transverse section of same showing excentric position of siphuncle. Machiakou 



limestone. Shantung. (Cotype, G. IS. Ch. Cat. No. o4;. (See further plate IX). 



Fig. 5. Actinoceras suhviarginaJc Grabau , p. 8G 



5a. Polished section through the siphuncle showing distant septa with camerse largely 



filled by stereoplasm. Also part of the endosiphuncle. Natural size. 

 5b. Transverse section of a part laterally displaced by a small fault, showing size and 

 submarginal position of siphuncle. Natural size. Machiakou limestone, Tangshan, 

 Chihli. (Cotype, G. S. Ch. Cat. No. 55). (See also plate IX). 



Fig. 6. Actinoceras curvatum Grabau p. 88 



A weathered specimen on rock showing curved form, septa with partial filling of 

 camerffi, and siphuncle. Natural size. Machiakou limestone, Lincheng, Shantung. 

 (Holotyye, F. F. Mathieu coll., G. S. Ch. Cat. No. 77) 



Fig. 7. Ci/rtacfinoceras freclii Grabau p. 89 



A weathered fragment near the apical end, showing siphuncle and septa, the camera; 

 scarcely obstructed by stereoplasm. The slight curvature scarcely appears in this 

 view. Natural size. Machiakou limestone, Tangshan. Chihli. (Cotype, T. C. 

 Wang coll. G. S. Ch. Cat. No. 2). 



Fig. 8. Ci/rtactinnceras frcclii (Jrabau , p. 89 



A small fragment near the apical end, showing sutures. Enlarged X 2. Machiakou 

 limestone. Chao-Kou-Chuang, Chihli. (Cotype, G. .8. Ch. Gat. No. 88). 



Fig. 9. Cyitacti/noccras freclii Grabau , p. 89 



9a. An apical portion somewhat weathered. Natural size. 



9b. Section of same, showing excentric siphuncle. Natural size. Machiakou limestone, 

 Shantung. (Cotype, G. S. Ch. Cat. No. GG). 



— 122 " 



