(ii) 30 Pakvontologia Sinica Ser. B. 



The endoconch is elliptical in transverse section, occupying the central position 

 of the ectoconch in the preserved part of the specimen. It is readily seen that the 

 interior of the endoconch is occupied by an endoseptum in the upper part of the pre- 

 served fragment and another one at the lower. The apical angle formed by these 

 conical endosepta are nearly the same, or about io°. The wall formed by the con- 

 tinuous tubi appears to have a zigzag outUnc in section and the width of the endoconch, 

 as exposed in the longitudinal section, varies from 7 mm. to 15 mm. narrowing in one 

 place and broadening in another. 



Neither the larger nor the smaller extremity has been observed. The fragment 

 measures more than one hundred and thirty milhmeters in length. The longer diameter 

 at the upper end of the shell is 45 mm., gradually contracting toward the smaller end 

 which is 25 mm. in diameter. This gives the rate of tapering i in 6.5. 



Ectotheca thin, but its surface characters unknown. No trace of any deposit is 

 found within the ectoconch or the endoconch. 



Comparison: This species is somewhat alhed to Endoceras magnivenWum Hall ' 

 from the higher part of the Trenton hmestone of New York State in the characters of 

 the close, strongly concave ectosepta and the undulating wall of siphonal tubi, but dif- 

 fers from the latter in the shghtly curved ectoconch, much narrower endoconch, and 

 more rapid tapering of the outer shell. The same characters are also used for distin- 

 guishing it from the preceding species. 



Horizon and Locality: From the argillaceous limestone bed of the Neichia- 

 shan formation at the small hill named Shih-lung-sze f 5 II ^ ) about ro li to the 

 west of Wang-chia-chi C i ^ ^ ), I-cheng-hsien. This species is named in honour of 

 Professor A. W. Grabau, Chief Palaeontologist to the Geological Survey. (Coll. W. P. 

 Shu and C. C. Yti) 



Genus VAGINOCERAS Hyatt 



Vaginoceras (Endoceras) wahlenbergi Foord. 



Plate III., Figs. la — b. 



i(S88. Endoceras Wahlanhergi, Foord: Catalogue of Fossil Cephalopoda, part I, p. 136, Text 



figs. II, 13, 14- 

 1895. Endoceras Wahlenbergi, Holm: Geol. Foren. Forh. i Stockholm, Bd. 17, Heft 6. 

 1917. Endoceras Wahlenbergi, Reed: Palseontologia Indica, New Series, Vol. VI, Mem. No. 3, p. 30, 

 pi. V, fig. II. 



I. J.Hall: Palaeontology of New, York, Vo.l I, p. 218, pi. LIII, figs, i a-e. 



