(ii) 24 Palieontologia Sinica Ser. B. 



specimen (Plate I., Fig. 3) the apical angle of the endosepta shown in the longitudinal 

 section is about 25"^. Endosiphuncle not observed. 



Remarks: The apical portion of the endoconch has not been preserved in the 

 specimen now at hand, so its generic identification (either as Cameroceras or Protero- 

 cameroceras) is not quite certain. According to its shorter length and other respects it 

 may be compared with Grabau's species^ collected from the Liangchiashan Hmestone 

 of Liang-chia-shan near Ching-wang-tao, eastern Chihli. 



Horizon and Locality: From the upper part of Ichang limestone at Lo-jo-ping 

 of I-chang-hsien (Coll. C. Y.Hsieh) 



Cameroceras tenuiseptum Hall var. ellipticum Ytj (var. nav.) 

 Plate II., Figs, i and 2. 



1847. Orthoceras tenuiseptum, Hall. Palaeontology of New York, Vol. i, p. 35, pi. VII, fig. 6. 



1902. Orthoceras tenuiseptum , Raymond. Am. Pal. Bui. Vol. I, No. 14, p. 19. 



1906. Cameroceras tenuiseptum, Ruedemann: New York State Museum. Bui. 90, p. 408, pi. 3, figs. 

 1,2; pi. 4, fig. i; pi. 5. figs. 5, 6; pi. 6, fig. 2. 



This form is only represented by fragments of the internal mold. Neither the 

 apical end nor the larger extremity is preserved. It had suffered so deeply from wea- 

 thering that the outer layer of the mold has turned into a very soft yellowish substance. 

 The ectoconch is robust and cylindrical in form. It is elliptical in cross section, the 

 ratio between the two diameters being 4:3, It tapers gently at the rate of nearly 1:13. 



The ectoseptal distances are very closely arranged, varying from 4-5 mm., while 

 the longer diameter of the ectoconch measures 43-50 mm. Roughh^ speaking the 

 ectosepta are distant about one tenth the longer diameter. The depth of the ectosepta 

 is very high, equalling that of three cameras. The ectosepal sutures are slightly un- 

 dulating. The ectoseptal chambers are more or less free from the organic deposit 

 except a few of them, in which the stereoplasmic deposit extends from the margin of the 

 shell toward the interior and stops at some distance from the endoconch. 



The endoconch is situated in close juxtaposition to the outer shell. Its cross 

 section too is elliptical. The endosepta have not been observed. The empty endocy- 



I. loc. cit. 



