PLATE III. 



Fig. I. Vaginoceras wahlenbergi Foord. X - p. 30 



la. A natural polished section, showing the rate of tapering and the 

 ectoseptal distances of the borken lower portion of the specimen. 



lb. Longitudinal section, showing the endoconch, the endocylinder, and 

 the ectosepta. The section is transverse to the dorso-ventral diameter 

 of the shell. 



Loc: — Tai-hung-shan, Nan-chang-hsien, N. Hupeh. (N.R.L Cat No. 4) 



7 

 Fig. 2. Vaginoceras endocylindricum Yii. x -^ p. 33 



2a. A natural section, showing the rate of tapering. 



2b. Cross section at the stage f of the same specimen, showing the forms 

 of ectoconch and the submarginal endoconch. 



2c. Longitudinal section of a fragmentary portion of the same shell, 

 showing the long endocylinder, endocone and the last endoseptum. 



2d. Cross section at the stage h of same, showing the submarginal 

 endoconch with a very small endosiphuncle at its middle part. 



Loc: — Ta-wu-shu, Chung-yang-hsien, SE. Hupeh. (N.R.L Cat. No. 7) 



Fig. 3. Vaginoceras endocylindricum Yii. Nat. size p. 33 



3a. View of a natural section weathered so as to show a part of the 

 endoconch preserved at the apical part of the fragment. 



3b. Cross section at the lower end of the shell, showing the form of 

 ectoconch and the position of the endoconch. 



Loc: — Ta-wu-shu, Chung-yang-hsien, SE. Hupeh. (N.R.L Cat. No. 8) 

 Fig. 4. Vaginoceras giganteum Yii. x - p. 45 



4a. Natural polished section, showing the rate of tapering, the depth of 

 septa and the endoconch. The endoconch at the middle part of the 

 specimen has been partly weathered away. 



4b. Cross section with an excentric endoconch. 



Loc: — Ta-wu-shu, Chung-yang-hsien, SE. Hupeh. (N.R.L Cat. No. 16) 



Fig. 5. Orthoceras chinense Foord. Nat. size p. a6 



5a. Longitudinal section, showing the length of septal necks, the depth of 

 cameree and the rate of tapering. 



5b. Cross section, showing the position of the rounded siphuncle. 



Tqc: — Near Sin-tan, Tze-kuei-hsien, W. Hupeh. (G.S.C. Cat. No. 2843) 



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