POEMATIOlSrS AND FOSSILS OF SOUTH MANCHUBIA 63 



limestone, North China. As both Grabau's and my specimens are 

 too poor to allow any exact determination of details, I have de- 

 scribed my specimen as allied to Gameroceras styliforTne Grabau. 

 The Manchurian specimen, however, differs in at least one or two 

 minor details, namely, in having comparatively larger dimensions 

 and from the North Chinese specimen, a more acute angle of the 

 annulations compared with the ventral line of the siphuncle. If in 

 the future I am able to obtain more and better specimens, this pos- 

 sible identity with G. styliforme may be definitely determined. The 

 Manchurian specimens may be described as follows : 



Description. — One of the specimens is 42.5 mm in length, consist- 

 ing of part of a siphuncle showing endocone, which enlarges slightly 

 from the base to the top. The surface of the siphuncle shows broad, 

 ill-defined annulations, and the angles between these and the ventral 

 line of the siphuncle are about 55°, the annulations being 2.5 in a 

 space of 10 mm. At the base of the specimen the section is suboval, 

 and here the dorsoventral and lateral diameters of the siphuncle 

 are 10 and 11.5 mm, respectively. The corresponding diameters of 

 the endocone are T.5 and 9 mm, respectively. In the same section 

 the endocone is in contact with the ventral wall of the siphuncle, 

 while the space between the dorsal surface of the endocone and the 

 corresponding surface of the siphuncle is estimated as 2.5 mm. Not 

 only the siphuncle but also the endocone is distinctly flattened ven- 

 trally. The interiors of both the siphuncle and the endocone are 

 filled by a calcareous matrix, and show no traces of the endosipho- 

 sheaths. 



Formation and locality. — Upper Canadian, Santao formation: In 

 the light gray limestone above the second tunnel, 1 mile north of 

 Pen-hsi-hu, Liao-tung, Manchuria. 



Genus PILOCERAS, Salter, 1859 



PILOCERAS MANCHURIENSE, new species 

 Plate 32, Figuees 5-7 ; Plate 33, Figuees 14, 15 



Description. — The holotype is 75 mm long, enlarging dorsoven- 

 trally very rapidly from the base to a point 22 mm farther up, in its 

 angle of enlargement being about 60° where it has reached a diameter 

 of 25.5 mm. From this point upward it enlarges more gradually, 

 attaining 32 mm at the top of the specimen. The surface of the 

 siphuncle is apparently annulated, the rings being transverse and not 

 showing any traces of oblique angles. These annulations are four 

 in a space of 10 mm. Where the dorsoventral diameter of the 

 siphuncle is 26 mm, the corresponding diameter of the endosiphuncle 

 is 8 mm, and here the space between it and the ventral surface of the 



