NO. 24 PTARMIGANIA STRATA RESSER 35 



glabella. Furrows are wide and shallow, and when the test is ex- 

 foliated they are traceable entirely across the glabella. The dorsal 

 furrow is shallow even though it is clearly defined. Evidently there 

 is a large, erect, occipital spine. The palpebral lobes at their widest 

 points are less than half the glabellar width. The eyes are long, with 

 a slightly thickened band, but not greatly curved, and are set prac- 

 tically parallel with the dorsal furrow. Compared to most of the 

 other species, this form is flat in cross section, with the glabella rising 

 above the palpebral lobes in a flat curvature. The fixigenes are prac- 

 tically flat and almost horizontal. Longitudinally there is more curva- 

 ture particularly because the anterior angles and posterolateral limbs 

 are depressed. The brim is simple, concave with a slightly upturned 

 rim. The pygidium is characterized by width of border and of the 

 marginal spines. The latter increase in size rearward so that the last 

 pair is large. The first segment is swollen as usual with a large spine, 

 and the axis overhangs the border in the rear. Fusion is carried so far 

 that most furrows are eliminated, and the border is wide. 



Locality 59c 



Holotype and paratype. — U.S.N.M. Nos. 98509a, b. 



DOLICHOMETOPSIS COMMUNIS, n. sp. 



Plate 6, figs. 5-8 



A number of specimens have been assigned to this species. It is 

 characterized by a glabella that expands slightly in front of the eyes 

 and has the usual shallow glabellar furrows. The distinctive charac- 

 teristics of the species are found in the palpebral lobes, which are 

 convex and narrow at their widest point, being only about one-third 

 as wide as the glabella. Eyes very long and not greatly curved. In 

 cross section the cranidium has a low-arched glabella and convex 

 palpebral lobes, which also rise above the dorsal furrow. On the other 

 hand, in longitudinal direction the cranidium is more highly arched, 

 curving slightly except in the anterior fourth, which is sharply down- 

 turned. The associated pygidium is characterized by the usual features 

 with the axis standing above the pleural lobes, but with only a 

 shallow dorsal furrow. The pits at the ends of the pleural furrows 

 are rather deep and the marginal spines nearly the same size through- 

 out are arranged in a stellate fashion. The surface is covered by 

 granules on the elevated portions, but the wide shallow furrows 

 lack them. 



Locality 54s. 



Holotype and paratype. — U.S.N.M. Nos. 98510a, b. 



