FORMATION'S AND FOSSILS OF SOUTH MAN'CHUIMA 65 



PENHSIOOERAS FUSIFORME, new species 



Plate 32, Figures 8-10 



Description. — The holotype specimen is 107 mm long, enlarging 

 very rapidly dorsoventrally from the base to a point 24 mm farther 

 up, its enlargement angle being 55° where it has reached a diameter 

 of 22 mm. From this point upward it decreases in diameter very 

 gradually to 16.5 mm near the top of the specimen and thus acquires 

 a general spindle shape. The cross sections of the siphuncle and 

 endosiphocone are apparently circular. The endosiphocone is rather 

 long, conical, alveolar toward the apex. At a point 11 mm below the 

 top, the dorsoventral diameter of the siphuncle is 17 mm, and the 

 corresponding diameter of the endosiphocone 8 mm. Here the space 

 between it and the ventral surface of the siphuncle is 2.5 mm, while 

 that between its dorsal surface and the corresponding surface of the 

 siphuncle is 6.5 mm, and in this section the endosiphocone is situated 

 very slightly ventrally. The endosiphocone tapers rapidly into the 

 endosiphotube at a point 34.5 mm below the top, and here the 

 diameter of the endosiphotube is estimated as 2 mm. The same 

 diameter of the endosiphotube obtains throughout the specimen from 

 this point to the apex. Unfortunately, as the interiors of the endo- 

 siphocone and siphuncle are filled entirely with calcareous matrix, 

 no internal structures can be determined, but some remains of endo- 

 siphosheaths are clearly retained. The surface of the siphuncle 

 is apparently annulated, these annulations being three in a space of 

 7 mm. 



A fragmental specimen of the apical part, which may belong to 

 the present species, was collected near Niu-hsin-tai. The interior 

 part of the siphuncle of this specimen, though filled by a calcareous 

 matrix, retains some relics of endosiphosheaths. 



Formation and localities. — Upper Canadian, Santao formation: 

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

 Pen-hsi-hu and at the same horizon near Ta-wan-kou, 1.5 miles 

 northeast of Niu-hsin-tai colliery, Liao-tung, Manchuria, 



Holotype and paratype.—JJ.^.'^.M. Nos. 83680 and 83681. 



Genus ORTHOCERAS Breynius, 1832 



ORTHOCERAS MAGNICHINENSE, new species 



Plate 38, Figueeis 1, 2 



Description. — Specimen 131 mm long, enlarging from a diameter 

 of 41 mm at the base to 77 mm at the top, the apical angle being 

 about 10°, The cross sections of the conch and siphuncle are circular. 

 The siphuncle is located centrally. Number of camerae in a length 

 equal to a diameter of conch is 1.8. The concavity of the septa 



