PALEONTOLOGY OF THE EUREKA DISTRICT. 



Genus BARRANDIA McCoy. 



Barrandia ? McCoyi, n. sp. 

 Plate xii, fig. 5. 



General form of glabella and fixed cheeks, exclusive of the extension 

 of the postero- lateral limbs, subquadrate. Glabella oblong, widening out a 

 little towards the broadly rounded front; general surface moderately con- 

 vex, and unbroken by any glabellar furrows; occipital ring of average 

 width; occipital furrow distinct, but not deeply impressed; dorsal furrows 

 quite strong in the specimen illustrated, and less so in other examples; 

 fixed cheeks of average width, broadest and most elevated at the eyelobes 

 from which they slope to the front and back; eyelobes situated back of a 

 line uniting their anterior margins with the center of the glabella; the 

 front of the head is bordered by a narrow, flattened rim; postero-lateral 

 limbs triangular, terminating at a distance from the dorsal furrow equal to 

 one-half the length of the glabella exclusive of the occipital ring. 



Surface smooth to the unaided eye. 



After an examination of the various species referred to this genus by 

 Mr. Salter, we find that the Eureka form differs from most of them in the 

 more anterior position of the eyelobes and the stronger dorsal furrows; 

 features that, without known differences in the thorax and pygidium to sup- 

 port them, we do not consider of generic importance. As the parts de- 

 scribed, however, are all that is known of the species, the generic reference 

 is somewhat provisional for this and also the following species. 



Formation and locality. Pogonip Group, on lower eastern slope of ridge 

 east of the Hamburg Ridge, Eureka District, Nevada. 



Barrandia? sp. T 

 Plate xii, fig. 6. 



Glabella subclavate, the width of the base being about four-fifths of 

 that of the anterior portion; front broadly rounded; general surface gently 

 convex, curving down somewhat abruptly in front to the narrow, rim-like 

 margin; occipital ring narrow and with a small tubercle at the center; 

 occipital furrow shallow, but quite distinct; dorsal furrows clearly defined. 



