CARBONIFEROUS PERIOD. 105 



anH immediately outside of that by another ring, which is so much elevated 

 as to form a little cup, with its rim somewhat expanded. Diameter of the 

 largest plate in the collection, about twenty millimeters. 



Spines very long and slender, one of those in the collection having 

 been, when perfect, about twelve centimeters in length, terete; diameter of 

 the basal ring, which expands abruptly from the shaft, greater than that of 

 any portion of the shaft; diameter of the shaft nearly uniform for more 

 than half its length above the basal ring, the upper portion gradually taper- 

 ing to a point. Greatest diametev of the shaft of the long spine referred to, 

 scarcely five millimeters; diameter of the basal ring, seven millimeters. 

 Sm-face of the spine for a short distance above the basal ring apparently 

 smooth, but, from that portion to the distal end, it is ornamented with 

 numerous small points or incipient spintiles, wliicli are often removed by 

 weathering, but, in well-preserved specimens, they are seen to be arranged 

 around the spine in imperfectly spiral lines. 



The very long, slender, terete spine, having a basal ring often much 

 greater in diameter than any part of the shaft, together with the other 

 characters described, distinguish this species from all others. 



Position and locality. — Strata of the Carboniferous period ("Red Wall 

 limestone"); Camp Apache, Arizona. 



MOLLUSCA. . 



MOLLIJSOIDEA. 



Class POLYZOA. 



Order GYMNOL^MATA. 

 Family MYRIAPOEIDiE. 



Genus GLAUCONOME Goldfuss, 1826. 



Glauconome nereidis White. 



Plate VII, fig. 5 a, h, c, d, and c. 



Glauconome nereidis White, 1874, Exp. & Surv. west 100th Merid., Prelim. Eep. Invert. 



Foss., IS. 



Polyzoary branching, the main stem sending off branches at irregular 

 intei^vals; these in like manner sending off secondary branches, but less 



