FOSSILS OF THE LOWEE SILURIAN. 



95 



Genus CEEAUEUS Green. 



Ceraurus? sp. undt. 

 Plate xii, fig. 17. 



Glabella subglobose, marked by two pairs of short furrows that are 

 only seen when looking from the sides; occipital segment strong; occipital 

 furrow well defined, also the dorsal furrows; fixed cheeks unknown except 

 a fragment near the dorsal furrow. Length of glabella, 3 mm ; width, 3.25 mm . 



This curious little species is referred to the genus provisionally, as 

 without other parts of the body its relations are not readily determined, 

 and on the same account the specific identification is not attempted. 



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

 next east of the Hamburg Ridge, Eureka District, Nevada. 



Genus SYMPHYSUEUS Goldfuss. 



Symphysurus ? Goldfussi, n. sp. 

 Plate xii, fig. 16. 



Glabella subclavate, convex, marked posteriorly by a pair of short, 

 lightly impressed furrows; occipital ring strong and separated from the 

 glabella by a well-defined but not deeply impressed furrow; dorsal furrows 

 strong but shallow; fixed cheeks of medium width, rising from the dorsal 

 furrows to the palpebral lobes, and sloping away to the front and back; 

 frontal limb very short, hardly more than a line within the narrow border; 

 postero-lateral limbs but little extended laterally, and marked by the exten- 

 sion of the occipital furrow across their posterior side. 



Surface apparently smooth. 



This species is referred to Symphysurus on account of the subclavate 

 glabella, and the direction of the facial sutures. In the absence of the 

 thorax and pygidium a close generic reference is almost impossible with 

 many of the species represented only by fragments. 



Formation and locality. Pogonip Group, on the west slope of McCoy's 

 Kidge, Eureka District, Nevada. 



