(ii) 40 Paheontologia Sinica Ser. B. 



Another one (PI. II., Fig. 7) expands its shell more slowly, the rate being 1:10. 

 The empty endocylinder is only preserved, indicating this fragment nearer the apertural 

 end. Seven camerii' are present. The ectosepta are slightly lined by the stereoplasm. 

 The size of the endocylinder and the ectoseptal intervals are similar to those in the 

 preceding specimen (PL I., Fig. 9). 



Comparison: In some respects this species is quite close to the Endocerds 

 proteiforme Hall ' from the Trenton formation of New York State, but our shell shows 

 the invaginated tubi, which is not a character given in the description by Hall. Accord- 

 ing to Clarke's statment the tubi of Endoceras proteiforme are short. Foerste says: 

 "Apparently they are only a single camera in length". But its diagrammatic sections 

 figured by Hyatt'-^ and Troedssons indicate that the tubi are longer than the length of 

 a camera. Even though the latter is the case in Hall's type, the present species may be 

 distinguished from it in having the ectoconch elliptical and the endoconch subcenlral and 

 circular. In Endoceras proteiforme the ectoconch is circular and the endoconch is mar- 

 ginal and elliptical'. It also differs from Vaginoceras vaginatum Schlotheim 5 in having 

 the more widely separated ectoseptal interspaces, smaller and subcentral endoconch; and 

 from Orthoceras [Endoceras) brongniartt Troost ^ in having the ectoconch less elliptical, 

 the endoconch comparatively larger, and the ectoseptal distance somewhat longer. 



Horizon and Localitiks: One specimen (PL II., Fig. 6) was collected by C. Li and 

 W. P. Shu from the reddish limestone of the Middle Ordovician age at San-shanyuan, 

 Chung-yang-hsien. The rest came from the upper part of the Neichiashan formation 

 near Sin-tan, western Hupeh. (Collected by J. L. Smith and C. Y. Hsieh respectively) 



Vaginoceras reedi YQ (sp. nov.) 



Plate I., Figs 10 a-c, 11 a-b. 



1017. Camerocerasl sp. Reed: Ordovician and Silurian fossils from Yunnan p. 35, pi. VI, figs, i, la. 

 1920. Orthoceras? sp. Yabe and Hayasaka: Palffiontology of Southern China, p. 49, pi, XVIII, 

 figs, 3; pi. XXVII, figs. 2 a-e. 



1. J. Hall: Paleontology of New York, Vol. I, p. 20S, pi. XLVIII, pi. XLIX, pi. L, pi. 

 LIII, figs. 2, pi. LVII. 



2. Zittel-Rastman: Text Book of Palaeontology, p. 595, fig. 1105. 



3. G. T. Troedsson: On the Middle and Upper Ordovician Faunas of Northern Greenland, I. 

 Cephalopoda, p. 27, pi. 8, fig. 4. 



4. G. T. Troedsson: On the Middle and Upper Ordovician Faunas of Northern Greenland. I. 

 Cephalopods. p. 27, pi. 7, figs, i, 2. 



5. Foord: Catalogues of Fossil Cephalopoda, Part I, p. 140. 



G. Blake: British Fossil Cephalopoda. Part I, p. 162, pi XVII, figs, i, la. 



