VOGDES ON SOME NEW SEDALIA TRILOBITES. 617 



nus. The amended genus has been used in the Paleontology of 

 New York, vol. 7, 1SS8, and also in the Bulletin of the Denison 

 University, vol. 4, 188S. Herrick describes four species under 

 this term, referring doubtless to the following species: Phcetho- 

 nides^l) imniaturus^ Herrick, and P.{J) Lodiensis^ Meek. The 

 last species has been desci-ibed both by English and American 

 authors under Brachymetopus. 



Under the law of priority Corda's genus should be used for 

 this section of Proetus and Forbesia^ McCoy, for such species 

 as Asaphus Stokesii,, Murch., which McCoy included under 

 Porbesia. 



The fimbricated pygidium alone is not worthy of generic clas- 

 sification, although a valuable guide in the identification of spe- 

 cies. Both plane and spinous pygidia are common in the genera 

 Agnost7is^ Bronteus^ Dalmanites^ Olenus, Paradoxides^ and 

 Proetus; and we may extend this characteristic to the genus 

 Brachymetopus by including the new species described in this 

 paper. Griffithides Sedaliensis probably belongs to the same 

 genus. 



In Brachyjnetopus armatus the posterior pleurae of the pygi- 

 dium are prolonged into spines ; a more characteristic and ex- 

 tended congeneric species of this type is one described from the 

 Cuyahoga shales of Ohio under the name of Dal?namites{}) 

 Cuvahogce^ by Prof. Claypole. In this species all the pleura ot 

 the pygidium are extended beyond the border into spines. 



Brachymetoi'us, McCoy. 

 Brachymetopus armatus, Vogdes. 

 Plate XV., figs. 4 and 5. 



DESCRIPTION. 



This new species is described from two fragments of the free 

 cheeks and six pygidia. The free cheeks are triangular in form, 

 bordered with an elevated ridge of equal width, the limb being 

 produced in rear into moderate spines. The interior parts of the 

 cheeks, between the eye and limb, slope gently, forming a de- 

 pressed area emarginating the limb. Palpebral lobes large, eyes 



