536 Bt: H. Woodward — M. Cambrian Fossils of the Rocldes. 



Neolenus granulatus, Matthew, 1899. 



Neolenus granulatus, G. F. Matthew, 1899 : Trans. Eoy. Soc. Canada [2], vol. v, 

 p. 55, pi. ii, figs. Ifl-c. 



(Very near to, if not identical with N. serratus.) M. Cambrian : 

 Mount Stephen. 



Ptychoparia CoRDiLLERiE, Walcott, 1888. 



Conocephalites Cordillerce, Roniinger, 1887: Proc. Acad. Nat. Sci. Philad., p. 17, 



pi. i, fig. 7. 

 Ptychoparia CordillercB, "Walcott, 1888 : Amer. Journ. Sci. [3], vol. xxxvi, p. 165. 

 Ptychoparia Cordillerm, G. F. Matthew, 1899: Trans. Eoy. Soc. Canada, sect, iv, 



pp. 44, 45, pi. i, fig. 7. 



Fig. 4. — Ptychoparia CordillercB, Eom., sp., 1887. 

 Middle Camhrian : Mount Stephen and Ball's Valley, B.C. Enlarged 3 times nat. size. 



Mr. Whymper's collection affords twelve specimens of this little 

 Trilobite, seven of which are from Ball's Valley and five from Mount 

 Stephen, B.C. Walcott states that he has seen a specimen of this 

 species [Ptychoparia Cordillera!) from Mount Stephen, 23 mm. in 

 length, which had nineteen thoracic segments, agreeing in this respect 

 with Ptychoparia Piochensis of Walcott, from the same horizon at 

 Pioche, Nevada. The head is, however, unlike the other species, 

 being more closely related to P. Kingi of Meek. (Amer. Journ. Sci. 

 [3], 1888, vol. xxxvi, p. 165.) 



G. F. Matthews says : " There appears to be some variation in the 

 number of joints in the thorax ; Dr. Eominger enumerates from 

 14 to 17, but the lower numbers were probably mutilated individuals. 

 . . . . The author has found 18 as a constant number in 

 examples 16 mm. in length and upwards to the adult." The 

 relative number of segments and the length in Ptychoparia Cordillene 

 are thus shown : — (Walcott), one specimen, 23 mm. long, with 19 

 thoracic segments; (Matthew), several specimens, 16 mm. long and 

 upwards to adult, 18 thoracic segments (constant) ; (Eominger), 

 several specimens, 25 mm. average length, 17 thoracic segments, 



