NO. 5 CAMBRIAN TRILOBITES 321 



(Billings) (pi. 57, fig. ic), as already indicated by Matthew.* Many 

 pygidia associated with the cranidia appear to have smooth antero- 

 lateral margins, but usually a trace of the spine may be found by 

 careful removal of the matrix. 



The associated pygidium described and figured by Billings has six 

 annulations on the axial lobe and four on the pleural lobes, as in 

 C. biibaris. This pygidium may belong with the cranidium, but I 

 find from the Bonne Bay locality that nearly all the pygidia are 

 shorter and have only four to five annulations including the terminal 

 one, and three to four that extend out onto the pleural lobes. The 

 collection from Bonne Bay includes over lOO cranidia, and as many 

 associated pygidia, and there are no other species of this type asso- 

 ciated with them. Even Corynexochus (Bonnia) parvidus is absent. 

 The pygidium figured by Billings is much like that of C. bitbaris 

 (pi. 56, fig. 3c?), which has four annulations in the axial lobe and three 

 on the pleural lobes. 



The cranidia are sometimes distorted so as to make elongate and 

 narrow forms; these are illustrated on plate 56, figure ic. 



Billings gives I'Anse au Loup on the Straits of Belle Isle as the 

 type locality of the species. Although we have quite large collections 

 from that area, no specimens of the species have been recognized, but 

 at Bonne Bay on the west side of Newfoundland the fragments of 

 the dorsal shield occur in large numbers in association with the 

 following fauna (locality 41 1) : 



Micromitra (Paterina) labradorica (Billings) 



Botsfordia calata (Hall) 



Kutorgina cingulata (Billings) 



Quebecia n. sp. 



Obolella chromatica Billings 



Pelagiella priniavum Billings 



Helcionella rugosa (Hall) 



Hyolithes billingsi Walcott 



Hyolithes princcps Billings 



Hyolithes coinmimis Billings 



Hyolithcllus micans (Billings) 



Salterella pulcheUa Billings 



Salterella rugosa Billings 



Olenellus thompsoni crassimarginatus Walcott 



Corynexochus senectus (Billings) 



The bed above the lituestone of 41 1 contains fragments of Olenellus 

 and numbers of Salterella. 



^ Trans. Royal Soc. Canada, 2d ser., Vol. 3, Sec. 4, 1897. pl- 4. fig- 5^. 



