NO. 5 CAMBRIAN TRILOBITES 315 



brings the pygidium near to those of Eurycare, Peltttra and other 

 genera having fringing spines on the border of the pygidium. 



The type specimens of this species are from a limestone boulder 

 in the Bic conglomerate and preserve the exterior surface, while 

 those identified with it from Vermont are in a shaly sandstone, and 

 those from Pennsylvania are in an arenaceous limestone. The latter 

 sometimes show traces of the granular surface so beautifully pre- 

 served in the limestone matrix. 



Specimens from the limestone near Emigsville, Pennsylvania 

 (locality 49w), show a granulated surface and an occipital spine 

 characteristic of the species. 



Formation and locality. — Lower Cambrian: (20) Limestone 

 boulders in conglomerate on shore at east entrance to harbor at Bic, 

 Rimouski County, Quebec, Canada. 



(49) Sandstone on Codorus Creek 0.125 mile (0.2 km.) below 

 Meyer's mill, near Emigsville; (49a) sandstone on the Liverpool 

 road, south of the schoolhouse, 3 miles (4.8 km.) northwest of York ; 

 and (49W) limestone in railroad cut, 0.25 mile (0.4 km.) south of 

 Emigsville railroad station ; all three localities in York County, 

 Pennsylvania. 



CORYNEXOCHUS CAPITO, new species 

 Plate 57, figs. 2, 2a-e 



Protypus scnectus Billings, Walcott, 1886, Bull. U. S. Geol. Surv., Vol. 30, 

 p. 213, pi. 31, figs. 2, 2a-c. (Prints original description with comments 

 and illustrates two cranidia and one associated pygidium from Ver- 

 mont.) 



Protypus senectus Lesley, 1889, Geol. Surv., Pa., Rept. P. 4, p. 784, 2 text 

 figs. only. (Compares with Angelin's Coryncxochus spimdosiis and 

 reproduces Walcott's figures of 1886.) 



Protypus senectus Walcott, 1891, Tenth Ann. Rept. U. S. Geol. Surv., p. 

 65s, pi. 98, figs. 7, ya-c. (Reproduces figures of 1886.) 



This form was formerly identified as the species senectus, but 

 with the specimens now available for study from Vermont and 

 York (Pennsylvania) it appears that a distinct species is present 

 that is neither C. senectus nor C. hubaris. The normal glabella is 

 broader than in other species and almost devoid of side furrows. 

 Anterior border narrow and close to the glabella ; palpebral lobes 

 small and narrow; occipital ring narrow and high at the posterior 

 center but without a spine as far as can be determined. 



The associated pygidia are larger and more rugged in appearance 

 than those associated with C. senectus. There is a small, short. 



